Search Results

Search found 1977 results on 80 pages for 'concurrent modification'.

Page 68/80 | < Previous Page | 64 65 66 67 68 69 70 71 72 73 74 75  | Next Page >

  • College Courses through distance learning

    - by Matt
    I realize this isn't really a programming question, but didn't really know where to post this in the stackexchange and because I am a computer science major i thought id ask here. This is pretty unique to the programmer community since my degree is about 95% programming. I have 1 semester left, but i work full time. I would like to finish up in December, but to make things easier i like to take online classes whenever I can. So, my question is does anyone know of any colleges that offer distance learning courses for computer science? I have been searching around and found a few potential classes, but not sure yet. I would like to gather some classes and see what i can get approval for. Class I need: Only need one C SC 437 Geometric Algorithms C SC 445 Algorithms C SC 473 Automata Only need one C SC 452 Operating Systems C SC 453 Compilers/Systems Software While i only need of each of the above courses i still need to take two more electives. These also have to be upper 400 level classes. So i can take multiple in each category. Some other classes I can take are: CSC 447 - Green Computing CSC 425 - Computer Networking CSC 460 - Database Design CSC 466 - Computer Security I hoping to take one or two of these courses over the summer. If not, then online over the regular semester would be ok too. Any help in helping find these classes would be awesome. Maybe you went to a college that offered distance learning. Some of these classes may be considered to be graduate courses too. Descriptions are listed below if you need. Thanks! Descriptions Computer Security This is an introductory course covering the fundamentals of computer security. In particular, the course will cover basic concepts of computer security such as threat models and security policies, and will show how these concepts apply to specific areas such as communication security, software security, operating systems security, network security, web security, and hardware-based security. Computer Networking Theory and practice of computer networks, emphasizing the principles underlying the design of network software and the role of the communications system in distributed computing. Topics include routing, flow and congestion control, end-to-end protocols, and multicast. Database Design Functions of a database system. Data modeling and logical database design. Query languages and query optimization. Efficient data storage and access. Database access through standalone and web applications. Green Computing This course covers fundamental principles of energy management faced by designers of hardware, operating systems, and data centers. We will explore basic energy management option in individual components such as CPUs, network interfaces, hard drives, memory. We will further present the energy management policies at the operating system level that consider performance vs. energy saving tradeoffs. Finally we will consider large scale data centers where energy management is done at multiple layers from individual components in the system to shutting down entries subset of machines. We will also discuss energy generation and delivery and well as cooling issues in large data centers. Compilers/Systems Software Basic concepts of compilation and related systems software. Topics include lexical analysis, parsing, semantic analysis, code generation; assemblers, loaders, linkers; debuggers. Operating Systems Concepts of modern operating systems; concurrent processes; process synchronization and communication; resource allocation; kernels; deadlock; memory management; file systems. Algorithms Introduction to the design and analysis of algorithms: basic analysis techniques (asymptotics, sums, recurrences); basic design techniques (divide and conquer, dynamic programming, greedy, amortization); acquiring an algorithm repertoire (sorting, median finding, strong components, spanning trees, shortest paths, maximum flow, string matching); and handling intractability (approximation algorithms, branch and bound). Automata Introduction to models of computation (finite automata, pushdown automata, Turing machines), representations of languages (regular expressions, context-free grammars), and the basic hierarchy of languages (regular, context-free, decidable, and undecidable languages). Geometric Algorithms The study of algorithms for geometric objects, using a computational geometry approach, with an emphasis on applications for graphics, VLSI, GIS, robotics, and sensor networks. Topics may include the representation and overlaying of maps, finding nearest neighbors, solving linear programming problems, and searching geometric databases.

    Read the article

  • Explaining Explain Plan Notes for Auto DOP

    - by jean-pierre.dijcks
    I've recently gotten some questions around "why do I not see a parallel plan" while Auto DOP is on (I think)...? It is probably worthwhile to quickly go over some of the ways to find out what Auto DOP was thinking. In general, there is no need to go tracing sessions and look under the hood. The thing to start with is to do an explain plan on your statement and to look at the parameter settings on the system. Parameter Settings to Look At First and foremost, make sure that parallel_degree_policy = AUTO. If you have that parameter set to LIMITED you will not have queuing and we will only do the auto magic if your objects are set to default parallel (so no degree specified). Next you want to look at the value of parallel_degree_limit. It is typically set to CPU, which in default settings equates to the Default DOP of the system. If you are testing Auto DOP itself and the impact it has on performance you may want to leave it at this CPU setting. If you are running concurrent statements you may want to give this some more thoughts. See here for more information. In general, do stick with either CPU or with a specific number. For now avoid the IO setting as I've seen some mixed results with that... In 11.2.0.2 you should also check that IO Calibrate has been run. Best to simply do a: SQL> select * from V$IO_CALIBRATION_STATUS; STATUS        CALIBRATION_TIME ------------- ---------------------------------------------------------------- READY         04-JAN-11 10.04.13.104 AM You should see that your IO Calibrate is READY and therefore Auto DOP is ready. In any case, if you did not run the IO Calibrate step you will get the following note in the explain plan: Note -----    - automatic DOP: skipped because of IO calibrate statistics are missing One more note on calibrate_io, if you do not have asynchronous IO enabled you will see:  ERROR at line 1: ORA-56708: Could not find any datafiles with asynchronous i/o capability ORA-06512: at "SYS.DBMS_RMIN", line 463 ORA-06512: at "SYS.DBMS_RESOURCE_MANAGER", line 1296 ORA-06512: at line 7 While this is changed in some fixes to the calibrate procedure, you should really consider switching asynchronous IO on for your data warehouse. Explain Plan Explanation To see the notes that are shown and explained here (and the above little snippet ) you can use a simple explain plan mechanism. There should  be no need to add +parallel etc. explain plan for <statement> SELECT PLAN_TABLE_OUTPUT FROM TABLE(DBMS_XPLAN.DISPLAY()); Auto DOP The note structure displaying why Auto DOP did not work (with the exception noted above on IO Calibrate) is like this: Automatic degree of parallelism is disabled: <reason> These are the reason codes: Parameter -  parallel_degree_policy = manual which will not allow Auto DOP to kick in  Hint - One of the following hints are used NOPARALLEL, PARALLEL(1), PARALLEL(MANUAL) Outline - A SQL outline of an older version (before 11.2) is used SQL property restriction - The statement type does not allow for parallel processing Rule-based mode - Instead of the Cost Based Optimizer the system is using the RBO Recursive SQL statement - The statement type does not allow for parallel processing pq disabled/pdml disabled/pddl disabled - For some reason (alter session?) parallelism is disabled Limited mode but no parallel objects referenced - your parallel_degree_policy = LIMITED and no objects in the statement are decorated with the default PARALLEL degree. In most cases all objects have a specific degree in which case Auto DOP will honor that degree. Parallel Degree Limited When Auto DOP does it works you may see the cap you imposed with parallel_degree_limit showing up in the note section of the explain plan: Note -----    - automatic DOP: Computed Degree of Parallelism is 16 because of degree limit This is an obvious indication that your are being capped for this statement. There is one quite interesting one that happens when you are being capped at DOP = 1. First of you get a serial plan and the note changes slightly in that it does not indicate it is being capped (we hope to update the note at some point in time to be more specific). It right now looks like this: Note -----    - automatic DOP: Computed Degree of Parallelism is 1 Dynamic Sampling With 11.2.0.2 you will start seeing another interesting change in parallel plans, and since we are talking about the note section here, I figured we throw this in for good measure. If we deem the parallel (!) statement complex enough, we will enact dynamic sampling on your query. This happens as long as you did not change the default for dynamic sampling on the system. The note looks like this: Note ----- - dynamic sampling used for this statement (level=5)

    Read the article

  • SQL SERVER – Recover the Accidentally Renamed Table

    - by pinaldave
    I have no answer to following question. I saw a desperate email marked as urgent delivered in my mailbox. “I accidentally renamed table in my SSMS. I was scrolling very fast and I made mistakes. It was either because I double clicked or clicked on F2 (shortcut key for renaming). However, I have made the mistake and now I have no idea how to fix this. I am in big trouble. Help me get my original tablename.” I have seen many similar scenarios in my life and they give me a very good opportunity to preach wisdom but when the house is burning, we cannot talk about how we should have conserved the water earlier. The goal at that point is to put off the fire as fast as we can. I decided to answer this email with my best knowledge. If you have renamed the table, I think you pretty much is out of luck. Here are few things which you can do which can give you idea about what your tablename can be if you are lucky. Method 1: (Not Recommended but try your luck) Check your naming convention of your system. I have often seen that many organizations name their index as IX_TableName_Colms or name their keys as FK_TableName1_TableName2_Cols. If your organization is following the same you can get the name from your table, you may refer your keys. Again, note that this is quite possible that your tablename was already renamed and your keys were not updated. This can easily lead you to select incorrect name. I think follow this if you are confident or move to the next method. Method 2: (Not Recommended but try your luck) This method is also based on your orgs naming convention. If you use the name of the table in any columnname (some organizations use tablename in their incremental identity column name), you can get that name from there. Method 3: (Not Recommended but try your luck) If you know where your table was used in your stored procedures, you can script your stored procedure and find the name of the table back. Method 4: (Try your luck) All the best organizations first create a data model of the schema and there is good chance that this table is used there, you should take your chances and refer original document. If your organization is good at managing docs or source code, you will get the name of the table back for sure. Method 5: (It WORKS but try on a development server) There is no sure way to get you the name of the table which you accidentally renamed however, there is one way which will work for sure. You need to take your latest full backup and restore it on your development server (remember not on production or where you have renamed this column). Now restore latest differential file of the full backup. Now restore all the log files one by one making sure that you are restoring before the point of time of you renamed the tablename. Now go to explore and this will give you the name of the table which you have renamed. If you are confident that the same table existed with the same name when the last full backup was made, you do not have to go to all the steps. You can just get the name of the table directly from last backup’s restore. Read the article about Backup Timeline. Wisdom: How can I miss to preach wisdom when I get the opportunity to do so? Here are a few points to remember. Use a different account to explore production environment. Do not use the same account which have all the rights and permissions all the time. Use the account which has read only permissions if there are no modification required. Use policy based management to prevent changes which are accidental. If there was policy of valid names, the accidental change of the table was not possible unless it was intentional delibarate changes. Have a proper auditing of the system in place. You can use DDL triggers but be careful with its usage (get it reviewed properly first). (Add your suggestion here) I guess Method 5 will work all the time (using point in time restore). Everything else is chance of luck and if you are lucky are bad – you will get further incorrect name. Now go back and read the first line of this blog. Out of five method four methods are just lucky guesses. The method 5 will work but again it is a lengthy process if the size of the database is huge or if you do not have full backup. Did I miss anything obvious? Please leave a comment and I will publish your answer with due credit. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: PostADay, SQL, SQL Authority, SQL Puzzle, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

    Read the article

  • JDK bug migration: components and subcomponents

    - by darcy
    One subtask of the JDK migration from the legacy bug tracking system to JIRA was reclassifying bugs from a three-level taxonomy in the legacy system, (product, category, subcategory), to a fundamentally two-level scheme in our customized JIRA instance, (component, subcomponent). In the JDK JIRA system, there is technically a third project-level classification, but by design a large majority of JDK-related bugs were migrated into a single "JDK" project. In the end, over 450 legacy subcategories were simplified into about 120 subcomponents in JIRA. The 120 subcomponents are distributed among 17 components. A rule of thumb used was that a subcategory had to have at least 50 bugs in it for it to be retained. Below is a listing the component / subcomponent classification of the JDK JIRA project along with some notes and guidance on which OpenJDK email addresses cover different areas. Eventually, a separate incidents project to host new issues filed at bugs.sun.com will use a slightly simplified version of this scheme. The preponderance of bugs and subcomponents for the JDK are in library-related areas, with components named foo-libs and subcomponents primarily named after packages. While there was an overall condensation of subcomponents in the migration, in some cases long-standing informal divisions in core libraries based on naming conventions in the description were promoted to formal subcomponents. For example, hundreds of bugs in the java.util subcomponent whose descriptions started with "(coll)" were moved into java.util:collections. Likewise, java.lang bugs starting with "(reflect)" and "(proxy)" were moved into java.lang:reflect. client-libs (Predominantly discussed on 2d-dev and awt-dev and swing-dev.) 2d demo java.awt java.awt:i18n java.beans (See beans-dev.) javax.accessibility javax.imageio javax.sound (See sound-dev.) javax.swing core-libs (See core-libs-dev.) java.io java.io:serialization java.lang java.lang.invoke java.lang:class_loading java.lang:reflect java.math java.net java.nio (Discussed on nio-dev.) java.nio.charsets java.rmi java.sql java.sql:bridge java.text java.util java.util.concurrent java.util.jar java.util.logging java.util.regex java.util:collections java.util:i18n javax.annotation.processing javax.lang.model javax.naming (JNDI) javax.script javax.script:javascript javax.sql org.openjdk.jigsaw (See jigsaw-dev.) security-libs (See security-dev.) java.security javax.crypto (JCE: includes SunJCE/MSCAPI/UCRYPTO/ECC) javax.crypto:pkcs11 (JCE: PKCS11 only) javax.net.ssl (JSSE, includes javax.security.cert) javax.security javax.smartcardio javax.xml.crypto org.ietf.jgss org.ietf.jgss:krb5 other-libs corba corba:idl corba:orb corba:rmi-iiop javadb other (When no other subcomponent is more appropriate; use judiciously.) Most of the subcomponents in the xml component are related to jaxp. xml jax-ws jaxb javax.xml.parsers (JAXP) javax.xml.stream (JAXP) javax.xml.transform (JAXP) javax.xml.validation (JAXP) javax.xml.xpath (JAXP) jaxp (JAXP) org.w3c.dom (JAXP) org.xml.sax (JAXP) For OpenJDK, most JVM-related bugs are connected to the HotSpot Java virtual machine. hotspot (See hotspot-dev.) build compiler (See hotspot-compiler-dev.) gc (garbage collection, see hotspot-gc-dev.) jfr (Java Flight Recorder) jni (Java Native Interface) jvmti (JVM Tool Interface) mvm (Multi-Tasking Virtual Machine) runtime (See hotspot-runtime-dev.) svc (Servicability) test core-svc (See serviceability-dev.) debugger java.lang.instrument java.lang.management javax.management tools The full JDK bug database contains entries related to legacy virtual machines that predate HotSpot as well as retired APIs. vm-legacy jit (Sun Exact VM) jit_symantec (Symantec VM, before Exact VM) jvmdi (JVM Debug Interface ) jvmpi (JVM Profiler Interface ) runtime (Exact VM Runtime) Notable command line tools in the $JDK/bin directory have corresponding subcomponents. tools appletviewer apt (See compiler-dev.) hprof jar javac (See compiler-dev.) javadoc(tool) (See compiler-dev.) javah (See compiler-dev.) javap (See compiler-dev.) jconsole launcher updaters (Timezone updaters, etc.) visualvm Some aspects of JDK infrastructure directly affect JDK Hg repositories, but other do not. infrastructure build (See build-dev and build-infra-dev.) licensing (Covers updates to the third party readme, licenses, and similar files.) release_eng (Release engineering) staging (Staging of web pages related to JDK releases.) The specification subcomponent encompasses the formal language and virtual machine specifications. specification language (The Java Language Specification) vm (The Java Virtual Machine Specification) The code for the deploy and install areas is not currently included in OpenJDK. deploy deployment_toolkit plugin webstart install auto_update install servicetags In the JDK, there are a number of cross-cutting concerns whose organization is essentially orthogonal to other areas. Since these areas generally have dedicated teams working on them, it is easier to find bugs of interest if these bugs are grouped first by their cross-cutting component rather than by the affected technology. docs doclet guides hotspot release_notes tools tutorial embedded build hotspot libraries globalization locale-data translation performance hotspot libraries The list of subcomponents will no doubt grow over time, but my inclination is to resist that growth since the addition of each subcomponent makes the system as a whole more complicated and harder to use. When the system gets closer to being externalized, I plan to post more blog entries describing recommended use of various custom fields in the JDK project.

    Read the article

  • Using a Predicate as a key to a Dictionary

    - by Tom Hines
    I really love Linq and Lambda Expressions in C#.  I also love certain community forums and programming websites like DaniWeb. A user on DaniWeb posted a question about comparing the results of a game that is like poker (5-card stud), but is played with dice. The question stemmed around determining what was the winning hand.  I looked at the question and issued some comments and suggestions toward a potential answer, but I thought it was a neat homework exercise. [A little explanation] I eventually realized not only could I compare the results of the hands (by name) with a certain construct – I could also compare the values of the individual dice with the same construct. That piece of code eventually became a Dictionary with the KEY as a Predicate<int> and the Value a Func<T> that returns a string from the another structure that contains the mapping of an ENUM to a string.  In one instance, that string is the name of the hand and in another instance, it is a string (CSV) representation of of the digits in the hand. An added benefit is that the digits re returned in the order they would be for a proper poker hand.  For instance the hand 1,2,5,3,1 would be returned as ONE_PAIR (1,1,5,3,2). [Getting to the point] 1: using System; 2: using System.Collections.Generic; 3:   4: namespace DicePoker 5: { 6: using KVP_E2S = KeyValuePair<CDicePoker.E_DICE_POKER_HAND_VAL, string>; 7: public partial class CDicePoker 8: { 9: /// <summary> 10: /// Magical construction to determine the winner of given hand Key/Value. 11: /// </summary> 12: private static Dictionary<Predicate<int>, Func<List<KVP_E2S>, string>> 13: map_prd2fn = new Dictionary<Predicate<int>, Func<List<KVP_E2S>, string>> 14: { 15: {new Predicate<int>(i => i.Equals(0)), PlayerTie},//first tie 16:   17: {new Predicate<int>(i => i > 0), 18: (m => string.Format("Player One wins\n1={0}({1})\n2={2}({3})", 19: m[0].Key, m[0].Value, m[1].Key, m[1].Value))}, 20:   21: {new Predicate<int>(i => i < 0), 22: (m => string.Format("Player Two wins\n2={2}({3})\n1={0}({1})", 23: m[0].Key, m[0].Value, m[1].Key, m[1].Value))}, 24:   25: {new Predicate<int>(i => i.Equals(0)), 26: (m => string.Format("Tie({0}) \n1={1}\n2={2}", 27: m[0].Key, m[0].Value, m[1].Value))} 28: }; 29: } 30: } When this is called, the code calls the Invoke method of the predicate to return a bool.  The first on matching true will have its value invoked. 1: private static Func<DICE_HAND, E_DICE_POKER_HAND_VAL> GetHandEval = dh => 2: map_dph2fn[map_dph2fn.Keys.Where(enm2fn => enm2fn(dh)).First()]; After coming up with this process, I realized (with a little modification) it could be called to evaluate the individual values in the dice hand in the event of a tie. 1: private static Func<List<KVP_E2S>, string> PlayerTie = lst_kvp => 2: map_prd2fn.Skip(1) 3: .Where(x => x.Key.Invoke(RenderDigits(dhPlayerOne).CompareTo(RenderDigits(dhPlayerTwo)))) 4: .Select(s => s.Value) 5: .First().Invoke(lst_kvp); After that, I realized I could now create a program completely without “if” statements or “for” loops! 1: static void Main(string[] args) 2: { 3: Dictionary<Predicate<int>, Action<Action<string>>> main = new Dictionary<Predicate<int>, Action<Action<string>>> 4: { 5: {(i => i.Equals(0)), PlayGame}, 6: {(i => true), Usage} 7: }; 8:   9: main[main.Keys.Where(m => m.Invoke(args.Length)).First()].Invoke(Display); 10: } …and there you have it. :) ZIPPED Project

    Read the article

  • SQL SERVER – Curious Case of Disappearing Rows – ON UPDATE CASCADE and ON DELETE CASCADE – Part 1 of 2

    - by pinaldave
    Social media has created an Always Connected World for us. Recently I enrolled myself to learn new technologies as a student. I had decided to focus on learning and decided not to stay connected on the internet while I am in the learning session. On the second day of the event after the learning was over, I noticed lots of notification from my friend on my various social media handle. He had connected with me on Twitter, Facebook, Google+, LinkedIn, YouTube as well SMS, WhatsApp on the phone, Skype messages and not to forget with a few emails. I right away called him up. The problem was very unique – let us hear the problem in his own words. “Pinal – we are in big trouble we are not able to figure out what is going on. Our product details table is continuously loosing rows. Lots of rows have disappeared since morning and we are unable to find why the rows are getting deleted. We have made sure that there is no DELETE command executed on the table as well. The matter of the fact, we have removed every single place the code which is referencing the table. We have done so many crazy things out of desperation but no luck. The rows are continuously deleted in a random pattern. Do you think we have problems with intrusion or virus?” After describing the problems he had pasted few rants about why I was not available during the day. I think it will be not smart to post those exact words here (due to many reasons). Well, my immediate reaction was to get online with him. His problem was unique to him and his team was all out to fix the issue since morning. As he said he has done quite a lot out in desperation. I started asking questions from audit, policy management and profiling the data. Very soon I realize that I think this problem was not as advanced as it looked. There was no intrusion, SQL Injection or virus issue. Well, long story short first - It was a very simple issue of foreign key created with ON UPDATE CASCADE and ON DELETE CASCADE.  CASCADE allows deletions or updates of key values to cascade through the tables defined to have foreign key relationships that can be traced back to the table on which the modification is performed. ON DELETE CASCADE specifies that if an attempt is made to delete a row with a key referenced by foreign keys in existing rows in other tables, all rows containing those foreign keys are also deleted. ON UPDATE CASCADE specifies that if an attempt is made to update a key value in a row, where the key value is referenced by foreign keys in existing rows in other tables, all of the foreign key values are also updated to the new value specified for the key. (Reference: BOL) In simple words – due to ON DELETE CASCASE whenever is specified when the data from Table A is deleted and if it is referenced in another table using foreign key it will be deleted as well. In my friend’s case, they had two tables, Products and ProductDetails. They had created foreign key referential integrity of the product id between the table. Now the as fall was up they were updating their catalogue. When they were updating the catalogue they were deleting products which are no more available. As the changes were cascading the corresponding rows were also deleted from another table. This is CORRECT. The matter of the fact, there is no error or anything and SQL Server is behaving how it should be behaving. The problem was in the understanding and inappropriate implementations of business logic.  What they needed was Product Master Table, Current Product Catalogue, and Product Order Details History tables. However, they were using only two tables and without proper understanding the relation between them was build using foreign keys. If there were only two table, they should have used soft delete which will not actually delete the record but just hide it from the original product table. This workaround could have got them saved from cascading delete issues. I will be writing a detailed post on the design implications etc in my future post as in above three lines I cannot cover every issue related to designing and it is also not the scope of the blog post. More about designing in future blog posts. Once they learn their mistake, they were happy as there was no intrusion but trust me sometime we are our own enemy and this is a great example of it. In tomorrow’s blog post we will go over their code and workarounds. Feel free to share your opinions, experiences and comments. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

    Read the article

  • To Bit or Not To Bit

    - by Johnm
    'Twas a long day of troubleshooting and firefighting and now, with most of the office vacant, you face a blank scripting window to create a new table in his database. Many questions circle your mind like dirty water gurgling down the bathtub drain: "How normalized should this table be?", "Should I use an identity column?", "NVarchar or Varchar?", "Should this column be NULLABLE?", "I wonder what apple blue cheese bacon cheesecake tastes like?" Well, there are times when the mind goes it's own direction. A Bit About Bit At some point during your table creation efforts you will encounter the decision of whether to use the bit data type for a column. The bit data type is an integer data type that recognizes only the values of 1, 0 and NULL as valid. This data type is often utilized to store yes/no or true/false values. An example of its use would be a column called [IsGasoline] which would be intended to contain the value of 1 if the row's subject (a car) had a gasoline engine and a 0 if the subject did not have a gasoline engine. The bit data type can even be found in some of the system tables of SQL Server. For example, the sysssispackages table in the msdb database which contains SQL Server Integration Services Package information for the packages stored in SQL Server. This table contains a column called [IsEncrypted]. A value of 1 indicates that the package has been encrypted while the value of 0 indicates that it is not. I have learned that the most effective way to disperse the crowd that surrounds the office coffee machine is to engage into SQL Server debates. The bit data type has been one of the most reoccurring, as well as the most enjoyable, of these topics. It contains a practical side and a philosophical side. Practical Consideration This data type certainly has its place and is a valuable option for database design; but it is often used in situations where the answer is really not a pure true/false response. In addition, true/false values are not very informative or scalable. Let's use the previously noted [IsGasoline] column for illustration. While on the surface it appears to be a rather simple question when evaluating a car: "Does the car have a gasoline engine?" If the person entering data is entering a row for a Jeep Liberty, the response would be a 1 since it has a gasoline engine. If the person is entering data is entering a row for a Chevrolet Volt, the response would be a 0 since it is an electric engine. What happens when a person is entering a row for the gasoline/electric hybrid Toyota Prius? Would one person's conclusion be consistent with another person's conclusion? The argument could be made that the current intent for the database is to be used only for pure gasoline and pure electric engines; but this is where the scalability issue comes into play. With the use of a bit data type a database modification and data conversion would be required if the business decided to take on hybrid engines. Whereas, alternatively, if the int data type were used as a foreign key to a reference table containing the engine type options, the change to include the hybrid option would only require an entry into the reference table. Philosophical Consideration Since the bit data type is often used for true/false or yes/no data (also called Boolean) it presents a philosophical conundrum of what to do about the allowance of the NULL value. The inclusion of NULL in a true/false or yes/no response simply violates the logical principle of bivalence which states that "every proposition is either true or false". If NULL is not true, then it must be false. The mathematical laws of Boolean logic support this concept by stating that the only valid values of this scenario are 1 and 0. There is another way to look at this conundrum: NULL is also considered to be the absence of a response. In other words, it is the equivalent to "undecided". Anyone who watches the news can tell you that polls always include an "undecided" option. This could be considered a valid option in the world of yes/no/dunno. Through out all of these considerations I have discovered one absolute certainty: When you have found a person, or group of persons, who are willing to entertain a philosophical debate of the bit data type, you have found some true friends.

    Read the article

  • InnoDB Compression Improvements in MySQL 5.6

    - by Inaam Rana
    MySQL 5.6 comes with significant improvements for the compression support inside InnoDB. The enhancements that we'll talk about in this piece are also a good example of community contributions. The work on these was conceived, implemented and contributed by the engineers at Facebook. Before we plunge into the details let us familiarize ourselves with some of the key concepts surrounding InnoDB compression. In InnoDB compressed pages are fixed size. Supported sizes are 1, 2, 4, 8 and 16K. The compressed page size is specified at table creation time. InnoDB uses zlib for compression. InnoDB buffer pool will attempt to cache compressed pages like normal pages. However, whenever a page is actively used by a transaction, we'll always have the uncompressed version of the page as well i.e.: we can have a page in the buffer pool in compressed only form or in a state where we have both the compressed page and uncompressed version but we'll never have a page in uncompressed only form. On-disk we'll always only have the compressed page. When both compressed and uncompressed images are present in the buffer pool they are always kept in sync i.e.: changes are applied to both atomically. Recompression happens when changes are made to the compressed data. In order to minimize recompressions InnoDB maintains a modification log within a compressed page. This is the extra space available in the page after compression and it is used to log modifications to the compressed data thus avoiding recompressions. DELETE (and ROLLBACK of DELETE) and purge can be performed without recompressing the page. This is because the delete-mark bit and the system fields DB_TRX_ID and DB_ROLL_PTR are stored in uncompressed format on the compressed page. A record can be purged by shuffling entries in the compressed page directory. This can also be useful for updates of indexed columns, because UPDATE of a key is mapped to INSERT+DELETE+purge. A compression failure happens when we attempt to recompress a page and it does not fit in the fixed size. In such case, we first try to reorganize the page and attempt to recompress and if that fails as well then we split the page into two and recompress both pages. Now lets talk about the three major improvements that we made in MySQL 5.6.Logging of Compressed Page Images:InnoDB used to log entire compressed data on the page to the redo logs when recompression happens. This was an extra safety measure to guard against the rare case where an attempt is made to do recovery using a different zlib version from the one that was used before the crash. Because recovery is a page level operation in InnoDB we have to be sure that all recompress attempts must succeed without causing a btree page split. However, writing entire compressed data images to the redo log files not only makes the operation heavy duty but can also adversely affect flushing activity. This happens because redo space is used in a circular fashion and when we generate much more than normal redo we fill up the space much more quickly and in order to reuse the redo space we have to flush the corresponding dirty pages from the buffer pool.Starting with MySQL 5.6 a new global configuration parameter innodb_log_compressed_pages. The default value is true which is same as the current behavior. If you are sure that you are not going to attempt to recover from a crash using a different version of zlib then you should set this parameter to false. This is a dynamic parameter.Compression Level:You can now set the compression level that zlib should choose to compress the data. The global parameter is innodb_compression_level - the default value is 6 (the zlib default) and allowed values are 1 to 9. Again the parameter is dynamic i.e.: you can change it on the fly.Dynamic Padding to Reduce Compression Failures:Compression failures are expensive in terms of CPU. We go through the hoops of recompress, failure, reorganize, recompress, failure and finally page split. At the same time, how often we encounter compression failure depends largely on the compressibility of the data. In MySQL 5.6, courtesy of Facebook engineers, we have an adaptive algorithm based on per-index statistics that we gather about compression operations. The idea is that if a certain index/table is experiencing too many compression failures then we should try to pack the 16K uncompressed version of the page less densely i.e.: we let some space in the 16K page go unused in an attempt that the recompression won't end up in a failure. In other words, we dynamically keep adding 'pad' to the 16K page till we get compression failures within an agreeable range. It works the other way as well, that is we'll keep removing the pad if failure rate is fairly low. To tune the padding effort two configuration variables are exposed. innodb_compression_failure_threshold_pct: default 5, range 0 - 100,dynamic, implies the percentage of compress ops to fail before we start using to padding. Value 0 has a special meaning of disabling the padding. innodb_compression_pad_pct_max: default 50, range 0 - 75, dynamic, the  maximum percentage of uncompressed data page that can be reserved as pad.

    Read the article

  • Polite busy-waiting with WRPAUSE on SPARC

    - by Dave
    Unbounded busy-waiting is an poor idea for user-space code, so we typically use spin-then-block strategies when, say, waiting for a lock to be released or some other event. If we're going to spin, even briefly, then we'd prefer to do so in a manner that minimizes performance degradation for other sibling logical processors ("strands") that share compute resources. We want to spin politely and refrain from impeding the progress and performance of other threads — ostensibly doing useful work and making progress — that run on the same core. On a SPARC T4, for instance, 8 strands will share a core, and that core has its own L1 cache and 2 pipelines. On x86 we have the PAUSE instruction, which, naively, can be thought of as a hardware "yield" operator which temporarily surrenders compute resources to threads on sibling strands. Of course this helps avoid intra-core performance interference. On the SPARC T2 our preferred busy-waiting idiom was "RD %CCR,%G0" which is a high-latency no-nop. The T4 provides a dedicated and extremely useful WRPAUSE instruction. The processor architecture manuals are the authoritative source, but briefly, WRPAUSE writes a cycle count into the the PAUSE register, which is ASR27. Barring interrupts, the processor then delays for the requested period. There's no need for the operating system to save the PAUSE register over context switches as it always resets to 0 on traps. Digressing briefly, if you use unbounded spinning then ultimately the kernel will preempt and deschedule your thread if there are other ready threads than are starving. But by using a spin-then-block strategy we can allow other ready threads to run without resorting to involuntary time-slicing, which operates on a long-ish time scale. Generally, that makes your application more responsive. In addition, by blocking voluntarily we give the operating system far more latitude regarding power management. Finally, I should note that while we have OS-level facilities like sched_yield() at our disposal, yielding almost never does what you'd want or naively expect. Returning to WRPAUSE, it's natural to ask how well it works. To help answer that question I wrote a very simple C/pthreads benchmark that launches 8 concurrent threads and binds those threads to processors 0..7. The processors are numbered geographically on the T4, so those threads will all be running on just one core. Unlike the SPARC T2, where logical CPUs 0,1,2 and 3 were assigned to the first pipeline, and CPUs 4,5,6 and 7 were assigned to the 2nd, there's no fixed mapping between CPUs and pipelines in the T4. And in some circumstances when the other 7 logical processors are idling quietly, it's possible for the remaining logical processor to leverage both pipelines. Some number T of the threads will iterate in a tight loop advancing a simple Marsaglia xor-shift pseudo-random number generator. T is a command-line argument. The main thread loops, reporting the aggregate number of PRNG steps performed collectively by those T threads in the last 10 second measurement interval. The other threads (there are 8-T of these) run in a loop busy-waiting concurrently with the T threads. We vary T between 1 and 8 threads, and report on various busy-waiting idioms. The values in the table are the aggregate number of PRNG steps completed by the set of T threads. The unit is millions of iterations per 10 seconds. For the "PRNG step" busy-waiting mode, the busy-waiting threads execute exactly the same code as the T worker threads. We can easily compute the average rate of progress for individual worker threads by dividing the aggregate score by the number of worker threads T. I should note that the PRNG steps are extremely cycle-heavy and access almost no memory, so arguably this microbenchmark is not as representative of "normal" code as it could be. And for the purposes of comparison I included a row in the table that reflects a waiting policy where the waiting threads call poll(NULL,0,1000) and block in the kernel. Obviously this isn't busy-waiting, but the data is interesting for reference. _table { border:2px black dotted; margin: auto; width: auto; } _tr { border: 2px red dashed; } _td { border: 1px green solid; } _table { border:2px black dotted; margin: auto; width: auto; } _tr { border: 2px red dashed; } td { background-color : #E0E0E0 ; text-align : right ; } th { text-align : left ; } td { background-color : #E0E0E0 ; text-align : right ; } th { text-align : left ; } Aggregate progress T = #worker threads Wait Mechanism for 8-T threadsT=1T=2T=3T=4T=5T=6T=7T=8 Park thread in poll() 32653347334833483348334833483348 no-op 415 831 124316482060249729303349 RD %ccr,%g0 "pause" 14262429269228623013316232553349 PRNG step 412 829 124616702092251029303348 WRPause(8000) 32443361333133483349334833483348 WRPause(4000) 32153308331533223347334833473348 WRPause(1000) 30853199322432513310334833483348 WRPause(500) 29173070315032223270330933483348 WRPause(250) 26942864294930773205338833483348 WRPause(100) 21552469262227902911321433303348

    Read the article

  • Mapping Repeating Sequence Groups in BizTalk

    - by Paul Petrov
    Repeating sequence groups can often be seen in real life XML documents. It happens when certain sequence of elements repeats in the instance document. Here’s fairly abstract example of schema definition that contains sequence group: <xs:schemaxmlns:b="http://schemas.microsoft.com/BizTalk/2003"            xmlns:xs="http://www.w3.org/2001/XMLSchema"            xmlns="NS-Schema1"            targetNamespace="NS-Schema1" >  <xs:elementname="RepeatingSequenceGroups">     <xs:complexType>       <xs:sequencemaxOccurs="1"minOccurs="0">         <xs:sequencemaxOccurs="unbounded">           <xs:elementname="A"type="xs:string" />           <xs:elementname="B"type="xs:string" />           <xs:elementname="C"type="xs:string"minOccurs="0" />         </xs:sequence>       </xs:sequence>     </xs:complexType>  </xs:element> </xs:schema> And here’s corresponding XML instance document: <ns0:RepeatingSequenceGroupsxmlns:ns0="NS-Schema1">  <A>A1</A>  <B>B1</B>  <C>C1</C>  <A>A2</A>  <B>B2</B>  <A>A3</A>  <B>B3</B>  <C>C3</C> </ns0:RepeatingSequenceGroups> As you can see elements A, B, and C are children of anonymous xs:sequence element which in turn can be repeated N times. Let’s say we need do simple mapping to the schema with similar structure but with different element names: <ns0:Destinationxmlns:ns0="NS-Schema2">  <Alpha>A1</Alpha>  <Beta>B1</Beta>  <Gamma>C1</Gamma>  <Alpha>A2</Alpha>  <Beta>B2</Beta>  <Gamma>C2</Gamma> </ns0:Destination> The basic map for such typical task would look pretty straightforward: If we test this map without any modification it will produce following result: <ns0:Destinationxmlns:ns0="NS-Schema2">  <Alpha>A1</Alpha>  <Alpha>A2</Alpha>  <Alpha>A3</Alpha>  <Beta>B1</Beta>  <Beta>B2</Beta>  <Beta>B3</Beta>  <Gamma>C1</Gamma>  <Gamma>C3</Gamma> </ns0:Destination> The original order of the elements inside sequence is lost and that’s not what we want. Default behavior of the BizTalk 2009 and 2010 Map Editor is to generate compatible map with older versions that did not have ability to preserve sequence order. To enable this feature simply open map file (*.btm) in text/xml editor and find attribute PreserveSequenceOrder of the root <mapsource> element. Set its value to Yes and re-test the map: <ns0:Destinationxmlns:ns0="NS-Schema2">  <Alpha>A1</Alpha>  <Beta>B1</Beta>  <Gamma>C1</Gamma>  <Alpha>A2</Alpha>  <Beta>B2</Beta>  <Alpha>A3</Alpha>  <Beta>B3</Beta>  <Gamma>C3</Gamma> </ns0:Destination> The result is as expected – all corresponding elements are in the same order as in the source document. Under the hood it is achieved by using one common xsl:for-each statement that pulls all elements in original order (rather than using individual for-each statement per element name in default mode) and xsl:if statements to test current element in the loop:  <xsl:templatematch="/s0:RepeatingSequenceGroups">     <ns0:Destination>       <xsl:for-eachselect="A|B|C">         <xsl:iftest="local-name()='A'">           <Alpha>             <xsl:value-ofselect="./text()" />           </Alpha>         </xsl:if>         <xsl:iftest="local-name()='B'">           <Beta>             <xsl:value-ofselect="./text()" />           </Beta>         </xsl:if>         <xsl:iftest="local-name()='C'">           <Gamma>             <xsl:value-ofselect="./text()" />           </Gamma>         </xsl:if>       </xsl:for-each>     </ns0:Destination>  </xsl:template> BizTalk Map editor became smarter so learn and use this lesser known feature of XSLT 2.0 in your maps and XSL stylesheets.

    Read the article

  • Updating a database connection password using a script

    - by Tim Dexter
    An interesting customer requirement that I thought was worthy of sharing today. Thanks to James for the requirement and Bryan for the proposed solution and me for testing the solution and proving it works :0) A customers implementation of Sarbanes Oxley requires them to change all database account passwords every 90 days. This is scripted leveraging shell scripts today for most of their environments. But how can they manage the BI Publisher connections? Now, the customer is running 11g and therefore using weblogic on the middle tier, which is the first clue to Bryans proposed solution. To paraphrase and embellish Bryan's solution a little; why not use a JNDI connection from BIP to the database. Then employ the web logic scripting engine to make updates to the JNDI as needed? BIP is completely uninvolved and with a little 'timing' users will be completely unaware of the password updates i.e. change the password when reports are not being executed. Perfect! James immediately tracked down the WLST script that could be used here, http://middlewaremagic.com/weblogic/?p=4261 (thanks Ravish) Now it was just a case of testing the theory. Some steps: Create the JNDI connection in WLS Create the JNDI connection in BI Publisher pointing to the WLS connection Build new data models using or re-point data sources to use the JNDI connection. Create the WLST script to update the WLS JNDI password as needed. Test! Some details. Creating the JNDI connection in web logic is pretty straightforward. Log into hte console and look for Data Sources under the Services section of the home page and click it Click New >> Generic Datasource Give the connection a name. For the JNDI name, prefix it with 'jdbc/' so I have 'jdbc/localdb' - this name is important you'll need it on the BIP side. Select your db type - this will influence the drivers and information needed on the next page. Being a company man, Im using an Oracle db. Click Next Select the driver of choice, theres lots I know, you can read about them I just chose 'Oracle's Driver (Thin) for Instance connections; Versions 9.0.1 and later' Click Next >> Next Fill out the db name (SID), server, port, username to connect and password >> Next Test the config to ensure you can connect. >> Next Now you need to deploy the connection to your BI server, select it and click Next. You're done with the JNDI config. Creating the JNDI connection on the Publisher side is covered here. Just remember to the connection name you created in WLS e.g. 'jdbc/localdb' Not gonna tell you how to do this, go read the user guide :0) Suffice to say, it works. This requires a little reading around the subject to understand the scripting engine and how to execute scripts. Nicely covered here. However a bit of googlin' and I found an even easier way of running the script. ${ServerHome}/common/bin/wlst.sh updatepwd.py Where updatepwd.py is my script file, it can be in another directory. As part of the wlst.sh script your environment is set up for you so its very simple to execute. The nitty gritty: Need to take Ravish's script above and create a file with a .py extension. Its going to need some modification, as he explains on the web page, to make it work in your environment. I played around with it for a while but kept running into errors. The script as is, tries to loop through all of your connections and modify the user and passwords for each. Not quite what we are looking for. Remember our requirement is to just update the password for a given connection. I also found another issue with the script. WLS 10.x does not allow updates to passwords using clear type ie un-encrypted text while the server is in production mode. Its a bit much to set it back to developer mode bounce it, change the passwords and then bounce and then change back to production and bounce again. After lots of messing about I finally came up with the following: ############################################################################# # # Update password for JNDI connections # ############################################################################# print("*** Trying to Connect.... *****") connect('weblogic','welcome1','t3://localhost:7001') print("*** Connected *****") edit() startEdit() print ("*** Encrypt the password ***") en = encrypt('hr') print "Encrypted pwd: ", en print ("*** Changing pwd for LocalDB ***") dsName = 'LocalDB' print 'Changing Password for DataSource ', dsName cd('/JDBCSystemResources/'+dsName+'/JDBCResource/'+dsName+'/JDBCDriverParams/'+dsName) set('PasswordEncrypted',en) save() activate() Its pretty simple and you can expand on it to loop through the data sources and change each as needed. I have hardcoded the password into the file but you can pass it as a parameter as needed using the properties file method. Im not going to get into the detail of that here but its covered with an example here. Couple of points to note: 1. The change to the password requires a server bounce to get the changes picked up. You can add that to the shell script you will use to call the script above. 2. The script above needs to be run from the MW_HOME\user_projects\domains\bifoundation_domain directory to get the encryption libraries set correctly. My command to run the whole script was: d:\oracle\bi_mw\wlserver_10.3\common\bin\wlst.cmd updatepwd.py - where wlst.cmd is the scripting command line and updatepwd.py was my update password script above. I have not quite spoon fed everything you need to make it a robust script but at least you know you can do it and you can work out the rest I think :0)

    Read the article

  • Disaster Recovery Discovery

    - by Rodney Landrum
    Last weekend I joined several of my IT staff on a mission to perform a DR test in our remote CoLo center in a large South East city of the US. Can I be more obtuse? The goal was simple for me as the sole DBA in a throng of Windows, Storage, Network and SAN admins – restore the databases and make them work. There were 4 applications that back ended to 7 SQL Server databases on 4 different SQL Server instances. We would maintain the original server names, but beyond that it was fair game. We had time to prepare so I was able to script out or otherwise automate the recovery process. I used sp_help_revlogin for three of the servers, a bit of a cheat actually because restoring the Master database on the target DR servers was the specified course of action according to the DR procedures ( the caveat “IF REQUIRED” left it open to interpretation. I really wanted to avoid the step of restoring Master for a number of reasons but mainly because I did not want to deal with issues starting SQL Services afterward. Having to account for the location of TempDB and the version conflicts of the resource DBs were just two of the battles I chose not to fight. Not to mention other system database location problems that might arise and prevent SQL from starting.  I was going to have to restore all of the user databases anyway, so I would not really gain any benefit, outside of logins, for taking the time to restore the source Master database over the newly installed one on the fresh server. What I wanted was the ability to restore the Master database as a user database, call it Master_Mine, from a backup on the source system and then use that restored database to script the SQL Logins and passwords on the DR systems. While I did not attempt this on the trip, the thought stuck in my mind and this past week I succeeded at scripting user accounts and passwords using only a restored copy of the Master database. Granted there were several challenges to overcome.  Also, as is usual for any work like this the usual disclaimers apply:  This is not something that I would imagine Microsoft would condone or support and this was really only an experiment for me to learn if it was even possible. While I have tested the process with success, I do not know that I would use this technique in a documented procedure because future updates for SQL Server will render this technique non-functional. I thought at first, incorrectly of course, that I could use sp_help_revlogin on a restored copy of the master database I named Master_Mine.   Since sp_help_revlogin uses system schema objects, sys.syslogins and sys.server_principals, this was not going to work because all results would come from the main Master database. To test this I added a SQL login via SSMS, backed up Master, restored  it as Master_Mine, and then deleted the login.  Even though the test account I created should presumably still be in the Master_Mine database, I should be able to get to it and script out its creation with its password hash so that I would not need to know the password, but any applications that stored that password would not have to be altered in the DR scenario. They would just work as expected. Once I realized that would not work I began looking deeper.  Knowing that sys.syslogins and sys.server_principals are system views, their underlying code should be available with sp_helptext, right? They were. And this led me to discover the two tables sys.sysxlgns and sys.sysprivs, where the data I needed was stored. These tables existed in both the real Master and the restored copy, Master_Mine.  I used this information to tweak the sp_help_revlogin stored procedure to use these tables instead to create the logins cursor used in sp_help_revlogin. For the password hash,  sp_help_revlogin uses the function LoginProperty() which takes a user name and option ‘passwordhash’ to return the hash for the user. Unfortunately, it requires the login to exist in the Master database. This would not work. So another slight modification I had to make was to pull the password hash itself (pwdhash from sys.sysxlgns) into the logins cursor and comment out the section of sp_help_revlogin that uses LoginProperty. Instead, I pass the pwdhash value as the variable @PWD_varbinary to the sp_hexadecimal stored procedure which is also created by and used within the code provided by Microsoft in the link above for sp_help_revlogin. The final challenge: sys.sysxlgns and sys.server_principals are visible only within a Dedicated Administrator Connection (DAC) query window in SSMS or within SQLCDMD.  To open a DAC connection you have to be logged in on the SQL Server itself, via RDP in my case,  and you preface the server name in the query connection with ADMIN:, so that the server connection looks like ADMIN:ServerName. From there you can create the modified stored procedure in the restored copy of a Master database from a source system as whatever name you like, and then run the modified stored procedure. I named my new stored procedure usp_help_revlogin_MyMaster. Upon execution I was happy to see the logins and password hashes that I needed to apply from the source Master database without having to restore over the new Master system database and without the need to access the original server (assuming it was down due to whatever disaster put it in that state). You will note that I am not providing full code samples here of the modifications. I will say that it was a slight bit of work and anyone who needed to do this for whatever reason, could fairly easily roll their own solution with the information provided herein.  My goal, as I said was to prove that this could be done and provide another option if required to ease the burden of getting SQL Servers up and available in an emergency situation where alternatives may be more challenging or otherwise unavailable.  

    Read the article

  • Windows in StreamInsight: Hopping vs. Snapshot

    - by Roman Schindlauer
    Three weeks ago, we explained the basic concept of windows in StreamInsight: defining sets of events that serve as arguments for set-based operations, like aggregations. Today, we want to discuss the so-called Hopping Windows and compare them with Snapshot Windows. We will compare these two, because they can serve similar purposes with different behaviors; we will discuss the remaining window type, Count Windows, another time. Hopping (and its syntactic-sugar-sister Tumbling) windows are probably the most straightforward windowing concept in StreamInsight. A hopping window is defined by its length, and the offset from one window to the next. They are aligned with some absolute point on the timeline (which can also be given as a parameter to the window) and create sets of events. The diagram below shows an example of a hopping window with length of 1h and hop size (the offset) of 15 minutes, hence creating overlapping windows:   Two aspects in this diagram are important: Since this window is overlapping, an event can fall into more than one windows. If an (interval) event spans a window boundary, its lifetime will be clipped to the window, before it is passed to the set-based operation. That’s the default and currently only available window input policy. (This should only concern you if you are using a time-sensitive user-defined aggregate or operator.) The set-based operation will be applied to each of these sets, yielding a result. This result is: A single scalar value in case of built-in or user-defined aggregates. A subset of the input payloads, in case of the TopK operator. Arbitrary events, when using a user-defined operator. The timestamps of the result are almost always the ones of the windows. Only the user-defined  operator can create new events with timestamps. (However, even these event lifetimes are subject to the window’s output policy, which is currently always to clip to the window end.) Let’s assume we were calculating the sum over some payload field: var result = from window in source.HoppingWindow( TimeSpan.FromHours(1), TimeSpan.FromMinutes(15), HoppingWindowOutputPolicy.ClipToWindowEnd) select new { avg = window.Avg(e => e.Value) }; Now each window is reflected by one result event:   As you can see, the window definition defines the output frequency. No matter how many or few events we got from the input, this hopping window will produce one result every 15 minutes – except for those windows that do not contain any events at all, because StreamInsight window operations are empty-preserving (more about that another time). The “forced” output for every window can become a performance issue if you have a real-time query with many events in a wide group & apply – let me explain: imagine you have a lot of events that you group by and then aggregate within each group – classical streaming pattern. The hopping window produces a result in each group at exactly the same point in time for all groups, since the window boundaries are aligned with the timeline, not with the event timestamps. This means that the query output will become very bursty, delivering the results of all the groups at the same point in time. This becomes especially obvious if the events are long-lasting, spanning multiple windows each, so that the produced result events do not change their value very often. In such a case, a snapshot window can remedy. Snapshot windows are more difficult to explain than hopping windows: they represent those periods in time, when no event changes occur. In other words, if you mark all event start and and times on your timeline, then you are looking at all snapshot window boundaries:   If your events are never overlapping, the snapshot window will not make much sense. It is commonly used together with timestamp modification, which make it a very powerful tool. Or as Allan Mitchell expressed in in a recent tweet: “I used to look at SnapshotWindow() with disdain. Now she is my mistress, the one I turn to in times of trouble and need”. Let’s look at a simple example: I want to compute the average of some value in my events over the last minute. I don’t want this output be produced at fixed intervals, but at soon as it changes (that’s the true event-driven spirit!). The snapshot window will include all currently active event at each point in time, hence we need to extend our original events’ lifetimes into the future: Applying the Snapshot window on these events, it will appear to be “looking back into the past”: If you look at the result produced in this diagram, you can easily prove that, at each point in time, the current event value represents the average of all original input event within the last minute. Here is the LINQ representation of that query, applying the lifetime extension before the snapshot window: var result = from window in source .AlterEventDuration(e => TimeSpan.FromMinutes(1)) .SnapshotWindow(SnapshotWindowOutputPolicy.Clip) select new { avg = window.Avg(e => e.Value) }; With more complex modifications of the event lifetimes you can achieve many more query patterns. For instance “running totals” by keeping the event start times, but snapping their end times to some fixed time, like the end of the day. Each snapshot then “sees” all events that have happened in the respective time period so far. Regards, The StreamInsight Team

    Read the article

  • How to handle updated configuration when it's already been cloned for editing

    - by alexrussell
    Really sorry about the title that probably doesn't make much sense. Hopefully I can explain myself better here as it's something that's kinda bugged me for ages, and is now becoming a pressing concern as I write a bit of software with configuration. Most software comes with default configuration options stored in the app itself, and then there's a configuration file (let's say) that a user can edit. Once created/edited for the first time, subsequent updates to the application can not (easily) modify this configuration file for fear of clobbering the user's own changes to the default configuration. So my question is, if my application adds a new configurable parameter, what's the best way to aid discoverability of the setting and allow the user (developer) to override it as nicely as possible given the following constraints: I actually don't have a canonical default config in the application per se, it's more of a 'cascading filesystem'-like affair - the config template is stored in default/config.json and when the user wishes to edit the configuration, it's copied to user/config.json. If a user config is found it is used - there is no automatic overriding of a subset of keys, the whole new file is used and that's that. If there's no user config the default config is used. When a user wishes to edit the config they run a command to 'generate' it for them (which simply copies the config.json file from the default to the user directory). There is no UI for the configuration options as it's not appropriate to the userbase (think of my software as a library or something, the users are developers, the config is done in the user/config.json file). Due to my software being library-like there's no simple way to, on updating of the software, run some tasks automatically (so any ideas of look at the current config, compare to template config, add ing missing keys) aren't appropriate. The only solution I can think of right now is to say "there's a new config setting X" in release notes, but this doesn't seem ideal to me. If you want any more information let me know. The above specifics are not actually 100% true to my situation, but they represent the problem equally well with lower complexity. If you do want specifics, however, I can explain the exact setup. Further clarification of the type of configuration I mean: think of the Atom code editor. There appears to be a default 'template' config file somewhere, but as soon as a configuration option is edited ~/.atom/config.cson is generated and the setting goes in there. From now on is Atom is updated and gets a new configuration key, this file cannot be overwritten by Atom without a lot of effort to ensure that the addition/modification of the key does not clobber. In Atom's case, because there is a GUI for editing settings, they can get away with just adding the UI for the new setting into the UI to aid 'discoverability' of the new setting. I don't have that luxury. Clarification of my constraints and what I'm actually looking for: The software I'm writing is actually a package for a larger system. This larger system is what provides the configuration, and the way it works is kinda fixed - I just do a config('some.key') kinda call and it knows to look to see if the user has a config clone and if so use it, otherwise use the default config which is part of my package. Now, while I could make my application edit the user's configuration files (there is a convention about where they're stored), it's generally not done, so I'd like to live with the constraints of the system I'm using if possible. And it's not just about discoverability either, one large concern is that the addition of a configuration key won't actually work as soon as the user has their own copy of the original template. Adding the key to the template won't make a difference as that file is never read. As such, I think this is actually quite a big flaw in the design of the configuration cascading system and thus needs to be taken up with my upstream. So, thinking about it, based on my constraints, I don't think there's going to be a good solution save for either editing the user's configuration or using a new config file every time there are updates to the default configuration. Even the release notes idea from above isn't doable as, if the user does not follow the advice, suddenly I have a config key with no value (user-defined or default). So the new question is this: what is the general way to solve the problem of having a default configuration in template config files and allowing a user to make user-specific version of these in order to override the defaults? A per-key cascade (rather than per-file cascade) where the user only specifies their overrides? In this case, what happens if a configuration value is an array - do we replace or append to the default (or, more realistically, how does the user specify whether they wish to replace or append to)? It seems like configuration is kinda hard, so how is it solved in the wild?

    Read the article

  • Subterranean IL: The ThreadLocal type

    - by Simon Cooper
    I came across ThreadLocal<T> while I was researching ConcurrentBag. To look at it, it doesn't really make much sense. What's all those extra Cn classes doing in there? Why is there a GenericHolder<T,U,V,W> class? What's going on? However, digging deeper, it's a rather ingenious solution to a tricky problem. Thread statics Declaring that a variable is thread static, that is, values assigned and read from the field is specific to the thread doing the reading, is quite easy in .NET: [ThreadStatic] private static string s_ThreadStaticField; ThreadStaticAttribute is not a pseudo-custom attribute; it is compiled as a normal attribute, but the CLR has in-built magic, activated by that attribute, to redirect accesses to the field based on the executing thread's identity. TheadStaticAttribute provides a simple solution when you want to use a single field as thread-static. What if you want to create an arbitary number of thread static variables at runtime? Thread-static fields can only be declared, and are fixed, at compile time. Prior to .NET 4, you only had one solution - thread local data slots. This is a lesser-known function of Thread that has existed since .NET 1.1: LocalDataStoreSlot threadSlot = Thread.AllocateNamedDataSlot("slot1"); string value = "foo"; Thread.SetData(threadSlot, value); string gettedValue = (string)Thread.GetData(threadSlot); Each instance of LocalStoreDataSlot mediates access to a single slot, and each slot acts like a separate thread-static field. As you can see, using thread data slots is quite cumbersome. You need to keep track of LocalDataStoreSlot objects, it's not obvious how instances of LocalDataStoreSlot correspond to individual thread-static variables, and it's not type safe. It's also relatively slow and complicated; the internal implementation consists of a whole series of classes hanging off a single thread-static field in Thread itself, using various arrays, lists, and locks for synchronization. ThreadLocal<T> is far simpler and easier to use. ThreadLocal ThreadLocal provides an abstraction around thread-static fields that allows it to be used just like any other class; it can be used as a replacement for a thread-static field, it can be used in a List<ThreadLocal<T>>, you can create as many as you need at runtime. So what does it do? It can't just have an instance-specific thread-static field, because thread-static fields have to be declared as static, and so shared between all instances of the declaring type. There's something else going on here. The values stored in instances of ThreadLocal<T> are stored in instantiations of the GenericHolder<T,U,V,W> class, which contains a single ThreadStatic field (s_value) to store the actual value. This class is then instantiated with various combinations of the Cn types for generic arguments. In .NET, each separate instantiation of a generic type has its own static state. For example, GenericHolder<int,C0,C1,C2> has a completely separate s_value field to GenericHolder<int,C1,C14,C1>. This feature is (ab)used by ThreadLocal to emulate instance thread-static fields. Every time an instance of ThreadLocal is constructed, it is assigned a unique number from the static s_currentTypeId field using Interlocked.Increment, in the FindNextTypeIndex method. The hexadecimal representation of that number then defines the specific Cn types that instantiates the GenericHolder class. That instantiation is therefore 'owned' by that instance of ThreadLocal. This gives each instance of ThreadLocal its own ThreadStatic field through a specific unique instantiation of the GenericHolder class. Although GenericHolder has four type variables, the first one is always instantiated to the type stored in the ThreadLocal<T>. This gives three free type variables, each of which can be instantiated to one of 16 types (C0 to C15). This puts an upper limit of 4096 (163) on the number of ThreadLocal<T> instances that can be created for each value of T. That is, there can be a maximum of 4096 instances of ThreadLocal<string>, and separately a maximum of 4096 instances of ThreadLocal<object>, etc. However, there is an upper limit of 16384 enforced on the total number of ThreadLocal instances in the AppDomain. This is to stop too much memory being used by thousands of instantiations of GenericHolder<T,U,V,W>, as once a type is loaded into an AppDomain it cannot be unloaded, and will continue to sit there taking up memory until the AppDomain is unloaded. The total number of ThreadLocal instances created is tracked by the ThreadLocalGlobalCounter class. So what happens when either limit is reached? Firstly, to try and stop this limit being reached, it recycles GenericHolder type indexes of ThreadLocal instances that get disposed using the s_availableIndices concurrent stack. This allows GenericHolder instantiations of disposed ThreadLocal instances to be re-used. But if there aren't any available instantiations, then ThreadLocal falls back on a standard thread local slot using TLSHolder. This makes it very important to dispose of your ThreadLocal instances if you'll be using lots of them, so the type instantiations can be recycled. The previous way of creating arbitary thread-static variables, thread data slots, was slow, clunky, and hard to use. In comparison, ThreadLocal can be used just like any other type, and each instance appears from the outside to be a non-static thread-static variable. It does this by using the CLR type system to assign each instance of ThreadLocal its own instantiated type containing a thread-static field, and so delegating a lot of the bookkeeping that thread data slots had to do to the CLR type system itself! That's a very clever use of the CLR type system.

    Read the article

  • Gamification = -10#/3mo

    - by erikanollwebb
    One of the purposes of gamification of anything is to see if you can modify the behavior of the user. In the enterprise, that might mean getting sales people to enter more information into a CRM system, encouraging employees to update their HR records, motivating people to participate in forums and discussions, or process invoices more quickly.  Wikipedia defines behavior modification as "the traditional term for the use of empirically demonstrated behavior change techniques to increase or decrease the frequency of behaviors, such as altering an individual's behaviors and reactions to stimuli through positive and negative reinforcement of adaptive behavior and/or the reduction of behavior through its extinction, punishment and/or satiation."  Gamification is just a way to modify someone's behavior using game mechanics. And the magic question is always whether it works. So I thought I would present my own little experiment from the last few months.  This spring, I upgraded to a Samsung Galaxy 4.  It's a pretty sweet phone in many ways, but one of the little extras I discovered was a built in app called S Health. S Health is an app that you can use to track calories, weight, exercise and it has a built in pedometer. I looked at it when I got the phone, but assumed you had to turn it on to use it so I didn't look at it much.  But sometime in July, I realized that in fact, it just ran in the background and was quietly tracking my steps, with a goal of 10,000 per day.  10,000 steps per day is this magic number recommended by the Surgeon General and the American Heart Association.  Dr. Oz pushes it as the goal for daily exercise.  It's about 5 miles of walking. I'm generally not the kind of person who always has my phone with me.  I leave it in my purse and pull it out when I need it.  But then I realized that meant I wasn't getting a good measure of my steps.  I decided to do a little experiment, and carry it with me as much as possible for a week.  That's when I discovered the gamification that changed my life over the last 3 months.  When I hit 10,000 steps, the app jingled out a little "success!" tune and I got a badge.  I was hooked.  I started carrying my phone.  I started making sure I had shoes I could walk in with me.  I started walking at lunch time, because I realized how often I sat at my desk for 8-10 hours every day without moving.  I started pestering my husband to walk with me after work because I hadn't hit my 10,000 yet, leading him at one point to say "I'm not as much a slave to that badge as you are!"  I started looking at parking lots differently.  Can't get a space up close?  No worries, just that many steps toward my 10,000.  I even tried to see if there was a second power user level at 15,000 or 20,000 (*sadly, no).  If I was close at the end of the day, I have done laps around my house until I got my badge.  I have walked around the block one more time to get my badge.  I have mentally chastised myself when I forgot to put my phone in my pocket because I don't know how many steps I got.  The badge below I got when my boss and I were in New York City and we walked around the block of our hotel just to watch the badge pop up. There are a bunch of tools out on the market now that have similar ideas for helping you to track your exercise, make it social.  There are apps (my favorite is still Zombies, Run!).  You could buy a FitBit or UP by Jawbone.   Interactive fitness makes the Expresso stationary bike with built in video games.  All designed to help you be more aware of your activity and keep you engaged and motivated.  And the idea is to help you change your behavior. I know someone who would spend extra time and work hard on the Expresso because he had built up strategies for how to kill the most dragons while he was riding to get more points.  When the machine broke down, he didn't ride a different bike because it just wasn't that interesting. But for me, just the simple jingle and badge have been all I needed.  I admit, I still giggle gleefully when I hear the tune sing out from my pocket. After a few weeks, I noticed I had dropped a few pounds.  Not a lot, just 2-3.  But then I was really hooked.  I started making a point both to eat a little less and hit 10,000 steps as much as I could.  I bemoaned that during the floods in Boulder, I wasn't hitting my 10,000 steps.  And now, a few months later, I'm almost 10 lbs lighter. All for 1 badge a day. So yes, simple gamification can increase motivation and engagement.  And that can lead to changes in behavior.  Now the job is to apply that to the enterprise space in a meaningful and engaging way. 

    Read the article

  • JPRT: A Build & Test System

    - by kto
    DRAFT A while back I did a little blogging on a system called JPRT, the hardware used and a summary on my java.net weblog. This is an update on the JPRT system. JPRT ("JDK Putback Reliablity Testing", but ignore what the letters stand for, I change what they mean every day, just to annoy people :\^) is a build and test system for the JDK, or any source base that has been configured for JPRT. As I mentioned in the above blog, JPRT is a major modification to a system called PRT that the HotSpot VM development team has been using for many years, very successfully I might add. Keeping the source base always buildable and reliable is the first step in the 12 steps of dealing with your product quality... or was the 12 steps from Alcoholics Anonymous... oh well, anyway, it's the first of many steps. ;\^) Internally when we make changes to any part of the JDK, there are certain procedures we are required to perform prior to any putback or commit of the changes. The procedures often vary from team to team, depending on many factors, such as whether native code is changed, or if the change could impact other areas of the JDK. But a common requirement is a verification that the source base with the changes (and merged with the very latest source base) will build on many of not all 8 platforms, and a full 'from scratch' build, not an incremental build, which can hide full build problems. The testing needed varies, depending on what has been changed. Anyone that was worked on a project where multiple engineers or groups are submitting changes to a shared source base knows how disruptive a 'bad commit' can be on everyone. How many times have you heard: "So And So made a bunch of changes and now I can't build!". But multiply the number of platforms by 8, and make all the platforms old and antiquated OS versions with bizarre system setup requirements and you have a pretty complicated situation (see http://download.java.net/jdk6/docs/build/README-builds.html). We don't tolerate bad commits, but our enforcement is somewhat lacking, usually it's an 'after the fact' correction. Luckily the Source Code Management system we use (another antique called TeamWare) allows for a tree of repositories and 'bad commits' are usually isolated to a small team. Punishment to date has been pretty drastic, the Queen of Hearts in 'Alice in Wonderland' said 'Off With Their Heads', well trust me, you don't want to be the engineer doing a 'bad commit' to the JDK. With JPRT, hopefully this will become a thing of the past, not that we have had many 'bad commits' to the master source base, in general the teams doing the integrations know how important their jobs are and they rarely make 'bad commits'. So for these JDK integrators, maybe what JPRT does is keep them from chewing their finger nails at night. ;\^) Over the years each of the teams have accumulated sets of machines they use for building, or they use some of the shared machines available to all of us. But the hunt for build machines is just part of the job, or has been. And although the issues with consistency of the build machines hasn't been a horrible problem, often you never know if the Solaris build machine you are using has all the right patches, or if the Linux machine has the right service pack, or if the Windows machine has it's latest updates. Hopefully the JPRT system can solve this problem. When we ship the binary JDK bits, it is SO very important that the build machines are correct, and we know how difficult it is to get them setup. Sure, if you need to debug a JDK problem that only shows up on Windows XP or Solaris 9, you'll still need to hunt down a machine, but not as a regular everyday occurance. I'm a big fan of a regular nightly build and test system, constantly verifying that a source base builds and tests out. There are many examples of automated build/tests, some that trigger on any change to the source base, some that just run every night. Some provide a protection gateway to the 'golden' source base which only gets changes that the nightly process has verified are good. The JPRT (and PRT) system is meant to guard the source base before anything is sent to it, guarding all source bases from the evil developer, well maybe 'evil' isn't the right word, I haven't met many 'evil' developers, more like 'error prone' developers. ;\^) Humm, come to think about it, I may be one from time to time. :\^{ But the point is that by spreading the build up over a set of machines, and getting the turnaround down to under an hour, it becomes realistic to completely build on all platforms and test it, on every putback. We have the technology, we can build and rebuild and rebuild, and it will be better than it was before, ha ha... Anybody remember the Six Million Dollar Man? Man, I gotta get out more often.. Anyway, now the nightly build and test can become a 'fetch the latest JPRT build bits' and start extensive testing (the testing not done by JPRT, or the platforms not tested by JPRT). Is it Open Source? No, not yet. Would you like to be? Let me know. Or is it more important that you have the ability to use such a system for JDK changes? So enough blabbering on about this JPRT system, tell me what you think. And let me know if you want to hear more about it or not. Stay tuned for the next episode, same Bloody Bat time, same Bloody Bat channel. ;\^) -kto

    Read the article

  • 4 Ways Your Brand Can Jump From the Edge of Space

    - by Mike Stiles
    Can your brand’s social media content captivate the world and make it hold its collective breath? Can you put something on the screen that’s so compelling that your audience can’t look away? Will they want to make sure their friends see it so they can talk about it? If not, you’re probably not with Red Bull. I was impressed with Red Bull’s approach to social content even before Felix Baumgartner’s stunning skydive from the edge of space. And then they did this. According to Visible Measures, videos of the jump scored 50 million views in 4 days. 1,700 clips were generated from both official and organic sources. The live stream was the most watched YouTube Stream of all time (8 million concurrent viewers). The 2nd most watched live stream was…Felix’ first attempt Oct. 9. Are you ready to compete with that? I ask that question because some brands are still out there tying themselves up in knots about whether or not they should tweet. The public’s time and attention are scarce commodities, commodities they value greatly. The competition amongst brands for that time and attention is intense and going up like Felix’s capsule. If you still view your press releases as “content,” you won’t even be counted as being among the competition. Here are 5 lessons learned from Red Bull’s big leap: 1. They have a total understanding of their target market and audience. Not only do they have an understanding of it, they do something about it. They act on it. They fill the majority of their thoughts with what the audience wants. They hunger for wild applause from that audience. They want to do things that embrace the audience’s lifestyle and immerse in it so the target will identify the brand as “one of them.” Takeaway: BE your target market. 2. They deliver content that strikes the audience right where they emotionally live. If you want your content to have impact, you have to make your audience’s heart race, or make them tear up, or make them laugh. Label them “data points” all you want, but humans are emotional creatures. No message connects that’s not carried in on an emotion. Takeaway: You’re on the inside. If your content doesn’t make you say “wow,” it’s unlikely it will register with fans. 3. They put aside old school marketing and don’t let their content be degraded into a commercial. Their execs seem to understand the value in keeping a lid on the hard sell. So many brands just can’t bring themselves to disconnect advertising and social content. The result is, otherwise decent content gets contaminated with a desperation the viewer can smell a mile away. Think the Baumgartner skydive didn’t do Red Bull any good since he wasn’t drinking one on the way down while singing a jingle? Analysis company Taykey discovered that at the peak of the skydive buzz, about 1% of all online conversation was about the jump. Mentions of Red Bull constituted 1/3 of 1% of all Internet activity. Views of other Red Bull videos also shot up. Takeaway: Chill out with the ads. Your brand will get full credit for entertaining/informing fans in a relevant way, provided you do it. 4. They don’t hesitate to ask, “What can we do next”? Most corporate cultures are a virtual training facility for “we can’t do that.” Few are encouraged to innovate or think big, if think at all. Thinking big involves faith, and work. It means freedom and letting employees run a little wild with their ideas. There will always be the opportunity to let fear of everything that moves creep in and kill grand visions dead in their tracks. Experimenting must be allowed. Failure must be allowed. Red Bull didn’t think big. They thought mega. They tried to outdo themselves. Felix could have gone ahead and jumped halfway up, thinking, “This is still relatively high up. Good enough.” But that wouldn’t have left us breathless. Takeaway: Go for it. Jump. In putting up social properties and gathering fans of your brand, you’ve basically invited people to a party. A good host doesn’t just set out warm beer and stale chips because that’s inexpensive and easy. Be on the lookout for ways to make your guests walk away saying, “That was epic.”

    Read the article

  • ADF Business Components

    - by Arda Eralp
    ADF Business Components and JDeveloper simplify the development, delivery, and customization of business applications for the Java EE platform. With ADF Business Components, developers aren't required to write the application infrastructure code required by the typical Java EE application to: Connect to the database Retrieve data Lock database records Manage transactions   ADF Business Components addresses these tasks through its library of reusable software components and through the supporting design time facilities in JDeveloper. Most importantly, developers save time using ADF Business Components since the JDeveloper design time makes typical development tasks entirely declarative. In particular, JDeveloper supports declarative development with ADF Business Components to: Author and test business logic in components which automatically integrate with databases Reuse business logic through multiple SQL-based views of data, supporting different application tasks Access and update the views from browser, desktop, mobile, and web service clients Customize application functionality in layers without requiring modification of the delivered application The goal of ADF Business Components is to make the business services developer more productive.   ADF Business Components provides a foundation of Java classes that allow your business-tier application components to leverage the functionality provided in the following areas: Simplifying Data Access Design a data model for client displays, including only necessary data Include master-detail hierarchies of any complexity as part of the data model Implement end-user Query-by-Example data filtering without code Automatically coordinate data model changes with business services layer Automatically validate and save any changes to the database   Enforcing Business Domain Validation and Business Logic Declaratively enforce required fields, primary key uniqueness, data precision-scale, and foreign key references Easily capture and enforce both simple and complex business rules, programmatically or declaratively, with multilevel validation support Navigate relationships between business domain objects and enforce constraints related to compound components   Supporting Sophisticated UIs with Multipage Units of Work Automatically reflect changes made by business service application logic in the user interface Retrieve reference information from related tables, and automatically maintain the information when the user changes foreign-key values Simplify multistep web-based business transactions with automatic web-tier state management Handle images, video, sound, and documents without having to use code Synchronize pending data changes across multiple views of data Consistently apply prompts, tooltips, format masks, and error messages in any application Define custom metadata for any business components to support metadata-driven user interface or application functionality Add dynamic attributes at runtime to simplify per-row state management   Implementing High-Performance Service-Oriented Architecture Support highly functional web service interfaces for business integration without writing code Enforce best-practice interface-based programming style Simplify application security with automatic JAAS integration and audit maintenance "Write once, run anywhere": use the same business service as plain Java class, EJB session bean, or web service   Streamlining Application Customization Extend component functionality after delivery without modifying source code Globally substitute delivered components with extended ones without modifying the application   ADF Business Components implements the business service through the following set of cooperating components: Entity object An entity object represents a row in a database table and simplifies modifying its data by handling all data manipulation language (DML) operations for you. These are basically your 1 to 1 representation of a database table. Each table in the database will have 1 and only 1 EO. The EO contains the mapping between columns and attributes. EO's also contain the business logic and validation. These are you core data services. They are responsible for updating, inserting and deleting records. The Attributes tab displays the actual mapping between attributes and columns, the mapping has following fields: Name : contains the name of the attribute we expose in our data model. Type : defines the data type of the attribute in our application. Column : specifies the column to which we want to map the attribute with Column Type : contains the type of the column in the database   View object A view object represents a SQL query. You use the full power of the familiar SQL language to join, filter, sort, and aggregate data into exactly the shape required by the end-user task. The attributes in the View Objects are actually coming from the Entity Object. In the end the VO will generate a query but you basically build a VO by selecting which EO need to participate in the VO and which attributes of those EO you want to use. That's why you have the Entity Usage column so you can see the relation between VO and EO. In the query tab you can clearly see the query that will be generated for the VO. At this stage we don't need it and just use it for information purpose. In later stages we might use it. Application module An application module is the controller of your data layer. It is responsible for keeping hold of the transaction. It exposes the data model to the view layer. You expose the VO's through the Application Module. This is the abstraction of your data layer which you want to show to the outside word.It defines an updatable data model and top-level procedures and functions (called service methods) related to a logical unit of work related to an end-user task. While the base components handle all the common cases through built-in behavior, customization is always possible and the default behavior provided by the base components can be easily overridden or augmented. When you create EO's, a foreign key will be translated into an association in our model. It defines the type of relation and who is the master and child as well as how the visibility of the association looks like. A similar concept exists to identify relations between view objects. These are called view links. These are almost identical as association except that a view link is based upon attributes defined in the view object. It can also be based upon an association. Here's a short summary: Entity Objects: representations of tables Association: Relations between EO's. Representations of foreign keys View Objects: Logical model View Links: Relationships between view objects Application Model: interface to your application  

    Read the article

  • Custom page sizes in paging dropdown in Telerik RadGrid

    Working with Telerik RadControls for ASP.NET AJAX is actually quite easy and the initial effort to get started with the control suite is very low. Meaning that you can easily get good result with little time. But there are usually cases where you have to go a little further and dig a little bit deeper than the standard scenarios. In this article I am going to describe how you can customize the default values (10, 20 and 50) of the drop-down list in the paging element of RadGrid. Get control over the displayed page sizes while using numeric paging... The default page sizes are good but not always good enough The paging feature in RadGrid offers you 3, well actually 4, possible page sizes in the drop-down element out-of-the box, which are 10, 20 or 50 items. You can get a fourth option by specifying a value different than the three standards for the PageSize attribute, ie. 35 or 100. The drawback in that case is that it is the initial page size. Certainly, the available choices could be more flexible or even a little bit more intelligent. For example, by taking the total count of records into consideration. There are some interesting scenarios that would justify a customized page size element: A low number of records, like 14 or similar shouldn't provide a page size of 50, A high total count of records (ie: 300+) should offer more choices, ie: 100, 200, 500, or display of all records regardless of number of records I am sure that you might have your own requirements, and I hope that the following source code snippets might be helpful. Wiring the ItemCreated event In order to adjust and manipulate the existing RadComboBox in the paging element we have to handle the OnItemCreated event of RadGrid. Simply specify your code behind method in the attribute of the RadGrid tag, like so: <telerik:RadGrid ID="RadGridLive" runat="server" AllowPaging="true" PageSize="20"    AllowSorting="true" AutoGenerateColumns="false" OnNeedDataSource="RadGridLive_NeedDataSource"    OnItemDataBound="RadGrid_ItemDataBound" OnItemCreated="RadGrid_ItemCreated">    <ClientSettings EnableRowHoverStyle="true">        <ClientEvents OnRowCreated="RowCreated" OnRowSelected="RowSelected" />        <Resizing AllowColumnResize="True" AllowRowResize="false" ResizeGridOnColumnResize="false"            ClipCellContentOnResize="true" EnableRealTimeResize="false" AllowResizeToFit="true" />        <Scrolling AllowScroll="true" ScrollHeight="360px" UseStaticHeaders="true" SaveScrollPosition="true" />        <Selecting AllowRowSelect="true" />    </ClientSettings>    <MasterTableView DataKeyNames="AdvertID">        <PagerStyle AlwaysVisible="true" Mode="NextPrevAndNumeric" />        <Columns>            <telerik:GridBoundColumn HeaderText="Listing ID" DataField="AdvertID" DataType="System.Int32"                SortExpression="AdvertID" UniqueName="AdvertID">                <HeaderStyle Width="66px" />            </telerik:GridBoundColumn>             <!--//  ... and some more columns ... -->         </Columns>    </MasterTableView></telerik:RadGrid> To provide a consistent experience for your visitors it might be helpful to display the page size selection always. This is done by setting the AlwaysVisible attribute of the PagerStyle element to true, like highlighted above. Customize the values of page size Your delegate method for the ItemCreated event should look like this: protected void RadGrid_ItemCreated(object sender, GridItemEventArgs e){    if (e.Item is GridPagerItem)    {        var dropDown = (RadComboBox)e.Item.FindControl("PageSizeComboBox");        var totalCount = ((GridPagerItem)e.Item).Paging.DataSourceCount;        var sizes = new Dictionary<string, string>() {            {"10", "10"},            {"20", "20"},            {"50", "50"}        };        if (totalCount > 100)        {            sizes.Add("100", "100");        }        if (totalCount > 200)        {            sizes.Add("200", "200");        }        sizes.Add("All", totalCount.ToString());        dropDown.Items.Clear();        foreach (var size in sizes)        {            var cboItem = new RadComboBoxItem() { Text = size.Key, Value = size.Value };            cboItem.Attributes.Add("ownerTableViewId", e.Item.OwnerTableView.ClientID);            dropDown.Items.Add(cboItem);        }        dropDown.FindItemByValue(e.Item.OwnerTableView.PageSize.ToString()).Selected = true;    }} It is important that we explicitly check the event arguments for GridPagerItem as it is the control that contains the PageSizeComboBox control that we want to manipulate. To keep the actual modification and exposure of possible page size values flexible I am filling a Dictionary with the requested 'key/value'-pairs based on the number of total records displayed in the grid. As a final step, ensure that the previously selected value is the active one using the FindItemByValue() method. Of course, there might be different requirements but I hope that the snippet above provide a first insight into customized page size value in Telerik's Grid. The Grid demos describe a more advanced approach to customize the Pager.

    Read the article

  • Is it feasible and useful to auto-generate some code of unit tests?

    - by skiwi
    Earlier today I have come up with an idea, based upon a particular real use case, which I would want to have checked for feasability and usefulness. This question will feature a fair chunk of Java code, but can be applied to all languages running inside a VM, and maybe even outside. While there is real code, it uses nothing language-specific, so please read it mostly as pseudo code. The idea Make unit testing less cumbersome by adding in some ways to autogenerate code based on human interaction with the codebase. I understand this goes against the principle of TDD, but I don't think anyone ever proved that doing TDD is better over first creating code and then immediatly therafter the tests. This may even be adapted to be fit into TDD, but that is not my current goal. To show how it is intended to be used, I'll copy one of my classes here, for which I need to make unit tests. public class PutMonsterOnFieldAction implements PlayerAction { private final int handCardIndex; private final int fieldMonsterIndex; public PutMonsterOnFieldAction(final int handCardIndex, final int fieldMonsterIndex) { this.handCardIndex = Arguments.requirePositiveOrZero(handCardIndex, "handCardIndex"); this.fieldMonsterIndex = Arguments.requirePositiveOrZero(fieldMonsterIndex, "fieldCardIndex"); } @Override public boolean isActionAllowed(final Player player) { Objects.requireNonNull(player, "player"); Hand hand = player.getHand(); Field field = player.getField(); if (handCardIndex >= hand.getCapacity()) { return false; } if (fieldMonsterIndex >= field.getMonsterCapacity()) { return false; } if (field.hasMonster(fieldMonsterIndex)) { return false; } if (!(hand.get(handCardIndex) instanceof MonsterCard)) { return false; } return true; } @Override public void performAction(final Player player) { Objects.requireNonNull(player); if (!isActionAllowed(player)) { throw new PlayerActionNotAllowedException(); } Hand hand = player.getHand(); Field field = player.getField(); field.setMonster(fieldMonsterIndex, (MonsterCard)hand.play(handCardIndex)); } } We can observe the need for the following tests: Constructor test with valid input Constructor test with invalid inputs isActionAllowed test with valid input isActionAllowed test with invalid inputs performAction test with valid input performAction test with invalid inputs My idea mainly focuses on the isActionAllowed test with invalid inputs. Writing these tests is not fun, you need to ensure a number of conditions and you check whether it really returns false, this can be extended to performAction, where an exception needs to be thrown in that case. The goal of my idea is to generate those tests, by indicating (through GUI of IDE hopefully) that you want to generate tests based on a specific branch. The implementation by example User clicks on "Generate code for branch if (handCardIndex >= hand.getCapacity())". Now the tool needs to find a case where that holds. (I haven't added the relevant code as that may clutter the post ultimately) To invalidate the branch, the tool needs to find a handCardIndex and hand.getCapacity() such that the condition >= holds. It needs to construct a Player with a Hand that has a capacity of at least 1. It notices that the capacity private int of Hand needs to be at least 1. It searches for ways to set it to 1. Fortunately it finds a constructor that takes the capacity as an argument. It uses 1 for this. Some more work needs to be done to succesfully construct a Player instance, involving the creation of objects that have constraints that can be seen by inspecting the source code. It has found the hand with the least capacity possible and is able to construct it. Now to invalidate the test it will need to set handCardIndex = 1. It constructs the test and asserts it to be false (the returned value of the branch) What does the tool need to work? In order to function properly, it will need the ability to scan through all source code (including JDK code) to figure out all constraints. Optionally this could be done through the javadoc, but that is not always used to indicate all constraints. It could also do some trial and error, but it pretty much stops if you cannot attach source code to compiled classes. Then it needs some basic knowledge of what the primitive types are, including arrays. And it needs to be able to construct some form of "modification trees". The tool knows that it needs to change a certain variable to a different value in order to get the correct testcase. Hence it will need to list all possible ways to change it, without using reflection obviously. What this tool will not replace is the need to create tailored unit tests that tests all kinds of conditions when a certain method actually works. It is purely to be used to test methods when they invalidate constraints. My questions: Is creating such a tool feasible? Would it ever work, or are there some obvious problems? Would such a tool be useful? Is it even useful to automatically generate these testcases at all? Could it be extended to do even more useful things? Does, by chance, such a project already exist and would I be reinventing the wheel? If not proven useful, but still possible to make such thing, I will still consider it for fun. If it's considered useful, then I might make an open source project for it depending on the time. For people searching more background information about the used Player and Hand classes in my example, please refer to this repository. At the time of writing the PutMonsterOnFieldAction has not been uploaded to the repo yet, but this will be done once I'm done with the unit tests.

    Read the article

  • The architecture and technologies to use for a secure, fast, reliable and easily scalable web application

    - by DSoul
    ^ For actual questions, skip to the lists down below I understand, that his is a vague topic, but please, before you turn the other way and disregard me, hear me out. I am currently doing research for a web application(I don't know if application is the correct word for it, but I will proceed w/ that for now), that one day might need to be everything mentioned in the title. I am bound by nothing. That means that every language, OS and framework is acceptable, but only if it proves it's usefulness. And if you are going to say, that scalability and speed depend on the code I write for this application, then I agree, but I am just trying to find something, that wouldn't stand in my way later on. I have done quite a bit reading on this subject, but I still don't have a clear picture, to what suits my needs, so I come to you, StackOverflow, to give me directions. I know you all must be wondering what I'm building, but I assure you, that it doesn't matter. I have heard of 12 factor app though, if you have any similar guidelines or what is, to suggest the please, go ahead. For the sake of keeping your answers as open as possible, I'm not gonna provide you my experience regarding anything written in this question. ^ Skippers, start here First off - the weights of the requirements are probably something like that (on a scale of 10): Security - 10 Speed - 5 Reliability (concurrency) - 7.5 Scalability - 10 Speed and concurrency are not a top priority, in the sense, that the program can be CPU intensive, and therefore slow, and only accept a not-that-high number of concurrent users, but both of these factors must be improvable by scaling the system Anyway, here are my questions: How many layers should the application have, so it would be future-proof and could best fulfill the aforementioned requirements? For now, what I have in mind is the most common version: Completely separated front end, that might be a web page or an MMI application or even both. Some middle-ware handling communication between the front and the back end. This is probably a server that communicates w/ the front end via HTTP. How the communication w/ the back end should be handled is probably dependent on the back end. The back end. Something that handles data through resources like DB and etc. and does various computations w/ the data. This, as the highest priority part of the software, must be easily spread to multiple computers later on and have no known security holes. I think ideally the middle-ware should send a request to a queue from where one of the back end processes takes this request, chops it up to smaller parts and buts these parts of the request back onto the same queue as the initial request, after what these parts will be then handled by other back end processes. Something *map-reduce*y, so to say. What frameworks, languages and etc. should these layers use? The technologies used here are not that important at this moment, you can ignore this part for now I've been pointed to node.js for this part. Do you guys know any better alternatives, or have any reasons why I should (not) use node.js for this particular job. I actually have no good idea, what to use for this job, there are too many options out there, so please direct me. This part (and the 2. one also, I think) depend a lot on the OS, so suggest any OSs alongside w/ the technologies/frameworks. Initially, all computers (or 1 for starters) hosting the back end are going to be virtual machines. Please do give suggestions to any part of the question, that you feel you have comprehensive knowledge and/or experience of. And also, point out if you feel that any part of the current set-up means an instant (or even distant) failure or if I missed a very important aspect to consider. I'm not looking for a definitive answer for how to achieve my goals, because there certainly isn't one, for I haven't provided you w/ all the required information. I'm just looking for recommendations and directions on what to look into. Also, bare in mind, that this isn't something that I have to get done quickly, to sell and let it be re-written by the new owner (which, I've been told for multiple times, is what I should aim for). I have all the time in the world and I really just want to learn doing something really high-end. Also, excuse me if my language isn't the best, I'm not a native. Anyway. Thanks in advance to anyone, who takes the time to help me out here. PS. When I do seem to come up w/ a good architecture/design for this project, I will certainly make it an open project and keep you guys up to date w/ it's development. As in what you could have told me earlier and etc. For obvious reasons the very same question got closed on SO, but could you guys still help me?.

    Read the article

  • Invalid or expired security context token in WCF web service

    - by Damian
    All, I have a WCF web service (let's called service "B") hosted under IIS using a service account (VM, Windows 2003 SP2). The service exposes an endpoint that use WSHttpBinding with the default values except for maxReceivedMessageSize, maxBufferPoolSize, maxBufferSize and some of the time outs that have been increased. The web service has been load tested using Visual Studio Load Test framework with around 800 concurrent users and successfully passed all tests with no exceptions being thrown. The proxy in the unit test has been created from configuration. There is a sharepoint application that use the Office Sharepoint Server Search service to call web services "A" and "B". The application will get data from service "A" to create a request that will be sent to service "B". The response coming from service "B" is indexed for search. The proxy is created programmatically using the ChannelFactory. When service "A" takes less than 10 minutes, the calls to service "B" are successfull. But when service "A" takes more time (~20 minutes) the calls to service "B" throw the following exception: Exception Message: An unsecured or incorrectly secured fault was received from the other party. See the inner FaultException for the fault code and detail Inner Exception Message: The message could not be processed. This is most likely because the action 'namespace/OperationName' is incorrect or because the message contains an invalid or expired security context token or because there is a mismatch between bindings. The security context token would be invalid if the service aborted the channel due to inactivity. To prevent the service from aborting idle sessions prematurely increase the Receive timeout on the service endpoint's binding. The binding settings are the same, the time in both client server and web service server are synchronize with the Windows Time service, same time zone. When i look at the server where web service "B" is hosted i can see the following security errors being logged: Source: Security Category: Logon/Logoff Event ID: 537 User NT AUTHORITY\SYSTEM Logon Failure: Reason: An error occurred during logon Logon Type: 3 Logon Process: Kerberos Authentication Package: Kerberos Status code: 0xC000006D Substatus code: 0xC0000133 After reading some of the blogs online, the Status code means STATUS_LOGON_FAILURE and the substatus code means STATUS_TIME_DIFFERENCE_AT_DC. but i already checked both server and client clocks and they are syncronized. I also noticed that the security token seems to be cached somewhere in the client server because they have another process that calls the web service "B" using the same service account and successfully gets data the first time is called. Then they start the proccess to update the office sharepoint server search service indexes and it fails. Then if they called the first proccess again it will fail too. Has anyone experienced this type of problems or have any ideas? Regards, --Damian

    Read the article

  • Unable to resolve class in build.gradle using Android Studio 0.60/Gradle 0.11

    - by saywhatnow
    Established app working fine using Android Studio 0.5.9/ Gradle 0.9 but upgrading to Android Studio 0.6.0/ Gradle 0.11 causes the error below. Somehow Studio seems to have lost the ability to resolve the android tools import at the top of the build.gradle file. Anyone got any ideas on how to solve this? build file 'Users/[me]/Repositories/[project]/[module]/build.gradle': 1: unable to resolve class com.android.builder.DefaultManifestParser @ line 1, column 1. import com.android.builder.DefaultManifestParser 1 error at org.codehaus.groovy.control.ErrorCollector.failIfErrors(ErrorCollector.java:302) at org.codehaus.groovy.control.CompilationUnit.applyToSourceUnits(CompilationUnit.java:858) at org.codehaus.groovy.control.CompilationUnit.doPhaseOperation(CompilationUnit.java:548) at org.codehaus.groovy.control.CompilationUnit.compile(CompilationUnit.java:497) at groovy.lang.GroovyClassLoader.doParseClass(GroovyClassLoader.java:306) at groovy.lang.GroovyClassLoader.parseClass(GroovyClassLoader.java:287) at org.gradle.groovy.scripts.internal.DefaultScriptCompilationHandler.compileScript(DefaultScriptCompilationHandler.java:115) ... 77 more 2014-06-09 10:15:28,537 [ 92905] INFO - .BaseProjectImportErrorHandler - Failed to import Gradle project at '/Users/[me]/Repositories/[project]' org.gradle.tooling.BuildException: Could not run build action using Gradle distribution 'http://services.gradle.org/distributions/gradle-1.12-all.zip'. at org.gradle.tooling.internal.consumer.ResultHandlerAdapter.onFailure(ResultHandlerAdapter.java:53) at org.gradle.tooling.internal.consumer.async.DefaultAsyncConsumerActionExecutor$1$1.run(DefaultAsyncConsumerActionExecutor.java:57) at org.gradle.internal.concurrent.DefaultExecutorFactory$StoppableExecutorImpl$1.run(DefaultExecutorFactory.java:64) [project]/[module]/build.gradle import com.android.builder.DefaultManifestParser apply plugin: 'android-sdk-manager' apply plugin: 'android' android { sourceSets { main { manifest.srcFile 'src/main/AndroidManifest.xml' res.srcDirs = ['src/main/res'] } debug { res.srcDirs = ['src/debug/res'] } release { res.srcDirs = ['src/release/res'] } } compileSdkVersion 19 buildToolsVersion '19.0.0' defaultConfig { minSdkVersion 14 targetSdkVersion 19 } signingConfigs { release } buildTypes { release { runProguard false proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.txt' signingConfig signingConfigs.release applicationVariants.all { variant -> def file = variant.outputFile def manifestParser = new DefaultManifestParser() def wmgVersionCode = manifestParser.getVersionCode(android.sourceSets.main.manifest.srcFile) println wmgVersionCode variant.outputFile = new File(file.parent, file.name.replace("-release.apk", "_" + wmgVersionCode + ".apk")) } } } packagingOptions { exclude 'META-INF/LICENSE.txt' exclude 'META-INF/NOTICE.txt' } } def Properties props = new Properties() def propFile = file('signing.properties') if (propFile.canRead()){ props.load(new FileInputStream(propFile)) if (props!=null && props.containsKey('STORE_FILE') && props.containsKey('STORE_PASSWORD') && props.containsKey('KEY_ALIAS') && props.containsKey('KEY_PASSWORD')) { println 'RELEASE BUILD SIGNING' android.signingConfigs.release.storeFile = file(props['STORE_FILE']) android.signingConfigs.release.storePassword = props['STORE_PASSWORD'] android.signingConfigs.release.keyAlias = props['KEY_ALIAS'] android.signingConfigs.release.keyPassword = props['KEY_PASSWORD'] } else { println 'RELEASE BUILD NOT FOUND SIGNING PROPERTIES' android.buildTypes.release.signingConfig = null } }else { println 'RELEASE BUILD NOT FOUND SIGNING FILE' android.buildTypes.release.signingConfig = null } repositories { maven { url 'https://repo.commonsware.com.s3.amazonaws.com' } maven { url 'https://oss.sonatype.org/content/repositories/snapshots/' } } dependencies { compile 'com.github.gabrielemariotti.changeloglib:library:1.4.+' compile 'com.google.code.gson:gson:2.2.4' compile 'com.google.android.gms:play-services:+' compile 'com.android.support:appcompat-v7:+' compile 'com.squareup.okhttp:okhttp:1.5.+' compile 'com.octo.android.robospice:robospice:1.4.11' compile 'com.octo.android.robospice:robospice-cache:1.4.11' compile 'com.octo.android.robospice:robospice-retrofit:1.4.11' compile 'com.commonsware.cwac:security:0.1.+' compile 'com.readystatesoftware.sqliteasset:sqliteassethelper:+' compile 'com.android.support:support-v4:19.+' compile 'uk.co.androidalliance:edgeeffectoverride:1.0.1+' compile 'de.greenrobot:eventbus:2.2.1+' compile project(':captureActivity') compile ('de.keyboardsurfer.android.widget:crouton:1.8.+') { exclude group: 'com.google.android', module: 'support-v4' } compile files('libs/CWAC-LoaderEx.jar') }

    Read the article

  • Memory Leak Issue in Weblogic, SUN, Apache and Oracle classes Options

    - by Amit
    Hi All, Please find below the description of memory leaks issues. Statistics show major growth in the perm area (static classes). Flows were ran for 8 hours , Heap dump was taken after 2 hours and at the end. A growth in Perm area was identified Statistics show from our last run 240MB growth in 6 hour,40mb growth every hour 2GB heap –can hold ¾ days ,heap will be full in ¾ days Heap dump show –growth in area as mentioned below JMS connection/session Area Apache org.apache.xml.dtm.DTM[] org.apache.xml.dtm.ref.ExpandedNameTable$ExtendedType org.jdom.AttributeList org.jdom.Content[] org.jdom.ContentList org.jdom.Element SUN * ConstantPoolCacheKlass * ConstantPoolKlass * ConstMethodKlass * MethodDataKlass * MethodKlass * SymbolKlass byte[] char[] com.sun.org.apache.xml.internal.dtm.DTM[] com.sun.org.apache.xml.internal.dtm.ref.ExtendedType java.beans.PropertyDescriptor java.lang.Class java.lang.Long java.lang.ref.WeakReference java.lang.ref.SoftReference java.lang.String java.text.Format[] java.util.concurrent.ConcurrentHashMap$Segment java.util.LinkedList$Entry Weblogic com.bea.console.cvo.ConsoleValueObject$PropertyInfo com.bea.jsptools.tree.TreeNode com.bea.netuix.servlets.controls.content.StrutsContent com.bea.netuix.servlets.controls.layout.FlowLayout com.bea.netuix.servlets.controls.layout.GridLayout com.bea.netuix.servlets.controls.layout.Placeholder com.bea.netuix.servlets.controls.page.Book com.bea.netuix.servlets.controls.window.Window[] com.bea.netuix.servlets.controls.window.WindowMode javax.management.modelmbean.ModelMBeanAttributeInfo weblogic.apache.xerces.parsers.SecurityConfiguration weblogic.apache.xerces.util.AugmentationsImpl weblogic.apache.xerces.util.AugmentationsImpl$SmallContainer weblogic.apache.xerces.util.SymbolTable$Entry weblogic.apache.xerces.util.XMLAttributesImpl$Attribute weblogic.apache.xerces.xni.QName weblogic.apache.xerces.xni.QName[] weblogic.ejb.container.cache.CacheKey weblogic.ejb20.manager.SimpleKey weblogic.jdbc.common.internal.ConnectionEnv weblogic.jdbc.common.internal.StatementCacheKey weblogic.jms.common.Item weblogic.jms.common.JMSID weblogic.jms.frontend.FEConnection weblogic.logging.MessageLogger$1 weblogic.logging.WLLogRecord weblogic.rjvm.BubblingAbbrever$BubblingAbbreverEntry weblogic.rjvm.ClassTableEntry weblogic.rjvm.JVMID weblogic.rmi.cluster.ClusterableRemoteRef weblogic.rmi.internal.CollocatedRemoteRef weblogic.rmi.internal.PhantomRef weblogic.rmi.spi.ServiceContext[] weblogic.security.acl.internal.AuthenticatedSubject weblogic.security.acl.internal.AuthenticatedSubject$SealableSet weblogic.servlet.internal.ServletRuntimeMBeanImpl weblogic.transaction.internal.XidImpl weblogic.utils.collections.ConcurrentHashMap$Entry Oracle XA Transaction oracle.jdbc.driver.Binder[] oracle.jdbc.driver.OracleDatabaseMetaData oracle.jdbc.driver.T4C7Ocommoncall oracle.jdbc.driver.T4C7Oversion oracle.jdbc.driver.T4C8Oall oracle.jdbc.driver.T4C8Oclose oracle.jdbc.driver.T4C8TTIBfile oracle.jdbc.driver.T4C8TTIBlob oracle.jdbc.driver.T4C8TTIClob oracle.jdbc.driver.T4C8TTIdty oracle.jdbc.driver.T4C8TTILobd oracle.jdbc.driver.T4C8TTIpro oracle.jdbc.driver.T4C8TTIrxh oracle.jdbc.driver.T4C8TTIuds oracle.jdbc.driver.T4CCallableStatement oracle.jdbc.driver.T4CClobAccessor oracle.jdbc.driver.T4CConnection oracle.jdbc.driver.T4CMAREngine oracle.jdbc.driver.T4CNumberAccessor oracle.jdbc.driver.T4CPreparedStatement oracle.jdbc.driver.T4CTTIdcb oracle.jdbc.driver.T4CTTIk2rpc oracle.jdbc.driver.T4CTTIoac oracle.jdbc.driver.T4CTTIoac[] oracle.jdbc.driver.T4CTTIoauthenticate oracle.jdbc.driver.T4CTTIokeyval oracle.jdbc.driver.T4CTTIoscid oracle.jdbc.driver.T4CTTIoses oracle.jdbc.driver.T4CTTIOtxen oracle.jdbc.driver.T4CTTIOtxse oracle.jdbc.driver.T4CTTIsto oracle.jdbc.driver.T4CXAConnection oracle.jdbc.driver.T4CXAResource oracle.jdbc.oracore.OracleTypeADT[] oracle.jdbc.xa.OracleXAResource$XidListEntry oracle.net.ano.Ano oracle.net.ns.ClientProfile oracle.net.ns.ClientProfile oracle.net.ns.NetInputStream oracle.net.ns.NetOutputStream oracle.net.ns.SessionAtts oracle.net.nt.ConnOption oracle.net.nt.ConnStrategy oracle.net.resolver.AddrResolution oracle.sql.CharacterSet1Byte we are using Oracle BEA Weblogic 9.2 MP3 JDK 1.5.12 Oracle versoin 10.2.0.4 (for oracle we found one path which is needed to applied to avoid XA transaction memory leaks). But we are stuck to resolve SUN, BEA Weblgogic and Apache leaks. please suggest... regards, Amit J.

    Read the article

< Previous Page | 64 65 66 67 68 69 70 71 72 73 74 75  | Next Page >