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  • Where can I get a list of PDF viewer/form-filler components for C#? [closed]

    - by Volomike
    Where can I get a list of recommended PDF viewer and form-filler components that I can buy and install in C#? I query on C# component PDF viewer on Google and get a lot of hits, but I'm not certain what programmers have tried and liked. Background: See, my employer is wanting me to build one in C# as a kind of training exercise, but also to be a product for sales lead generation for another product they sell. The employer is perfectly okay buying something, as long as it's good. I've learned VB6 and PHP, and know a little C and C++, so I'm trying to learn where people get the best-rated addon components for it, and especially for this PDF viewer and form filler thing he wants.

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  • 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.  

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  • Oracle Sequences

    - by jkrebsbach
    Reminder to myself - SQL Server has nice index columns directly tied to their tables. Oracle has sequences that are islands to themselves. select seq_name.currval from dual; select seq_name.nextval from dual; currval - return current number at top of sequence nextval - increment sequence by 1, return new number   therefore - to create functionality in oracle similar to an index column - OPTION A) - Create insert trigger: CREATE OR REPLACE TRIGGER dept_bir BEFORE INSERT ON departments FOR EACH ROW WHEN (new.id IS NULL) BEGIN SELECT dept_seq.NEXTVAL INTO :new.id FROM dual; END; This will handle creating a unique identity, but will not necessarily inform process flow of identity without additional logic. OPTION B) - Select indentity into temp variable, insert whole item into tab **** When attemptint to query currval, the below error was being thrown - SELECT seq_name.currval from dual; ERROR : TABLE OR VIEW DOES NOT EXIST *** Although Oracle sys tables may have access to the sequences, that isn't to say the Oracle user may have access to those sequences - verify permissions when the system can't see object that are being reported in the object explorer.

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  • Transmitting Form Data from the Client to the Web Server

    The steps involved in transmitting form data from the client to the web server User loads web form User enters data in to web form fields User clicks submit On submit page validates fields using JavaScript. If validation errors are found then the validation script stops the browser from canceling posting the data to the web server and displays error messages as needed If the form passes the data validation process then the browser will URL encode the values of every field and post it to the server.  The server reads the posted data from the query string and then again validates the data just to ensure data consistency and to prevent any non-validated data because JavaScript was turned off on the clients browser from being inserted in to a database or passed on to other process If the data passes the second validation check then the server side code will continue with the requested processes

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  • Why should I use List<T> over IEnumerable<T>?

    - by Rowan Freeman
    In my ASP.net MVC4 web application I use IEnumerables, trying to follow the mantra to program to the interface, not the implementation. Return IEnumerable(Of Student) vs Return New List(Of Student) People are telling me to use List and not IEnumerable, because lists force the query to be executed and IEumerable does not. Is this really best practice? Is there any alternative? I feel strange using concrete objects where an interface could be used. Is my strange feeling justified?

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  • Save BIG on Storage &mdash; with Oracle Advanced Compression

    - by [email protected]
    Recently, we published a podcast revealing just how much Oracle benefits from its internal use of Oracle Database 11g and Advanced Compression. With hundreds of TB and millions of dollars saved, Oracle Advanced Compression is dramatically reducing storage costs and substantially improving efficiency across the company. Now, here's your chance: Meet the experts, have your questions answered by them and immediately start using your storage more efficiently: On April 14th, join me for a live Webcast with Oracle's Tim Shetler, Vice President of Product Management and Bill Hodak, Principal Product Manager, to learn just how Oracle Advanced Compression can Reduce disk space requirements for all types of data Improve query and storage performance Lower storage costs throughout the datacenter Register here! var gaJsHost = (("https:" == document.location.protocol) ? "https://ssl." : "http://www."); document.write(unescape("%3Cscript src='" + gaJsHost + "google-analytics.com/ga.js' type='text/javascript'%3E%3C/script%3E")); try { var pageTracker = _gat._getTracker("UA-13185312-1"); pageTracker._trackPageview(); } catch(err) {}

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  • Does semi-normalization exist as a concept? Is it "normalized"?

    - by Gracchus
    If you don't mind, a tldr on my experience: My experience tldr I have an application that's heavily dependent upon uncertainty, a bane to database design. I tried to normalize it as best as I could according to the capabilities of my database of choice, but a "simple" query took 50ms to read. Nosql appeals to me, but I can't trust myself with it, and besides, normalization has cut down my debugging time immensely over and over. Instead of 100% normalization, I made semi-redundant 1:1 tables with very wide primary keys and equivalent foreign keys. Read times dropped to a few ms, and write times barely degraded. The semi-normalized point Given this reality, that anyone who's tried to rely upon views of fully normalized data is aware of, is this concept codified? Is it as simple as having wide unique and foreign keys, or are there any hidden secrets to this technique? Or is uncertainty merely a special case that has extremely limited application and can be left on the ash heap?

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  • SQL Down Under Show 51 - Guest Conor Cunningham - Now online

    - by Greg Low
    Late last night I got to record an interview with Conor Cunningham.Most people that know Conor have come across him as the product team wizard that knows so much about query processing and optimization in SQL Server. Conor is currently spending quite a lot of time working on Windows Azure SQL Database, which we used to know as SQL Azure. I'm still trying to think of a good way to say "WASD". I suppose I'll pronounce it like "wassid". Windows Azure SQL Reporting is easier. I think it just needs to be pronounced like "wazza" with a very Australian accent.In the show, we've spent time on the current state of the platform, on dispelling a number of common misbeliefs about the product, and hopefully on answering most of the common questions that seem to get asked about it. We then ventured into Federations, Data Sync, and Reporting.You'll find the show (and previous shows) here: http://www.sqldownunder.com/Resources/Podcast.aspxEnjoy!PS: For those that like transcripts, we've got the process for producing them much improved now and the transcript should also be up within a few days.

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  • Is Java's ElementCollection Considered a Bad Practice?

    - by SoulBeaver
    From my understanding, an ElementCollection has no primary key, is embedded with the class, and cannot be queried. This sounds pretty hefty, but it allows me the comfort of writing an enum class which also helps with internationalization (using the enum key for lookup in my ResourceBundle). Example: We have a user on a media site and he can choose in which format he downloads the files @Entity @Table(name = "user") public class User { /* snip other fields */ @Enumerated @ElementCollection( targetClass = DownloadFilePreference.class, fetch = FetchType.EAGER ) @CollectionTable(name = "download_file_preference", joinColumns = @JoinColumn(name = "user_id") ) @Column(name = "name") private Set<DownloadFilePreference> downloadFilePreferences = new HashSet<>(); } public enum DownloadFilePreference { MP3, WAV, AIF, OGG; } This seems pretty great to me, and I suppose it comes down to "it depends on your use case", but I also know that I'm quite frankly only an initiate when it comes to Database design. Some best practices suggest to never have a class without a primary key- even in this case? It also doesn't seem very extensible- should I use this and gamble on the chance I will never need to query on the FilePreferences?

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  • Partitioning tutorial - new features in Oracle Database 12c

    - by KLaker
    For data warehousing projects Oracle Partitioning really is a must-have feature because it delivers so many important benefits such as: Dramatically improves query performance and speeds up database maintenance operations Lowers costs by enabling a tiered storage approach that allows data to be stored on the most cost-effective storage for better resource utilisation Combined with Oracle Advanced Compression, it provides an automated approach to information lifecycle management using a simple, efficient, yet powerful way to manage data growth and reduce complexity and costs To help you get the most from partitioning we have released a new tutorial that covers the 12c new features. Topics include how to: Use Interval Reference Partitioning Perform Cascading TRUNCATE and EXCHANGE Operations Move Partitions Online Maintain Multiple Partitions Maintain Global Indexes Asynchronously Use Partial Indexes For more information about this tutorial follow this link to the Oracle Learning Library: http://apex.oracle.com/pls/apex/f?p=44785:24:0::NO:24:P24_CONTENT_ID,P24_PREV_PAGE:8408,2 where you can begin your tutorial right now! For more information about Oracle Partitioning visit our home page on OTN: http://www.oracle.com/technetwork/database/bi-datawarehousing/dbbi-tech-info-part-100980.html

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  • Node.js Or servlets?

    - by Nilesh
    I have heard a lot and read about the Javascript server side language i.e Node.js, and saw many comparisons in favor of Node. I don't understand what makes it better or faster, or how it even relates to something as mature as Java Servlets. But Servlets are built on top of a multithreaded programming language as opposed to Node.js. Then how can node.js be faster? If suppose 1000K users query for a database records, then shouldn't Node.js be slower than Servlets. Also Don't servlets have better security compared to Node.js?

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  • Distinct Count of Customers in a SCD Type 2 in #DAX

    - by Marco Russo (SQLBI)
    If you have a Slowly Changing Dimension (SCD) Type 2 for your customer and you want to calculate the number of distinct customers that bought a product, you cannot use the simple formula: Customers := DISTINCTCOUNT( FactTable[Customer Id] ) ) because it would return the number of distinct versions of customers. What you really want to do is to calculate the number of distinct application keys of the customers, that could be a lower number than the number you’ve got with the previous formula. Assuming that a Customer Code column in the Customers dimension contains the application key, you should use the following DAX formula: Customers := COUNTROWS( SUMMARIZE( FactTable, Customers[Customer Code] ) ) Be careful: only the version above is really fast, because it is solved by xVelocity (formerly known as VertiPaq) engine. Other formulas involving nested calculations might be more complex and move computation to the formula engine, resulting in slower query. This is absolutely an interesting pattern and I have to say it’s a killer feature. Try to do the same in Multidimensional…

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  • MDW Reports–New Source Code ZIP File Available

    - by billramo
    In my MDW Reports series, I attached V1 of the RDL files in my post - May the source be with you! MDW Report Series Part 6–The Final Edition. Since that post, Rachna Agarwal from MSIT in India updated the RDL files that are ready to go in a single ZIP. The reports assume that they will ne uploaded to the Report Manager’s root folder and use a shared data source named MDW. The reports also integrate with the new Query Hash Statistics reports. You can download them from my SQLBlog.com download site.

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  • Fast set indexing data structure for superset retrieval

    - by Asterios
    I am given a set of sets: {{a,b}, {a,b,c}, {a,c}, {a,c,f}} I would like to have a data structure to index those sets such that the following "lookup" is executed fast: find all supersets of a given set. For example, given the set {a,c} the structure would return {{a,b,c}, {a,c,f}, {a,c}} but not {a,b}. Any suggestions? Could this be done with a smart trie-like data structure storing sets after a proper sorting? This data structures is going to be queried a lot. Thus, I'm searching for a structure that might be expensive in build but rather fast to query.

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  • How-to populate different select list content per table row

    - by frank.nimphius
    Normal 0 false false false EN-US X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} A frequent requirement posted on the OTN forum is to render cells of a table column using instances of af:selectOneChoices with each af:selectOneChoice instance showing different list values. To implement this use case, the select list of the table column is populated dynamically from a managed bean for each row. The table's current rendered row object is accessible in the managed bean using the #{row} expression, where "row" is the value added to the table's var property. <af:table var="row">   ...   <af:column ...>     <af:selectOneChoice ...>         <f:selectItems value="#{browseBean.items}"/>     </af:selectOneChoice>   </af:column </af:table> The browseBean managed bean referenced in the code snippet above has a setItems and getItems method defined that is accessible from EL using the #{browseBean.items} expression. When the table renders, then the var property variable - the #{row} reference - is filled with the data object displayed in the current rendered table row. The managed bean getItems method returns a List<SelectItem>, which is the model format expected by the f:selectItems tag to populate the af:selectOneChoice list. public void setItems(ArrayList<SelectItem> items) {} //this method is executed for each table row public ArrayList<SelectItem> getItems() {   FacesContext fctx = FacesContext.getCurrentInstance();   ELContext elctx = fctx.getELContext();   ExpressionFactory efactory =          fctx.getApplication().getExpressionFactory();          ValueExpression ve =          efactory.createValueExpression(elctx, "#{row}", Object.class);      Row rw = (Row) ve.getValue(elctx);         //use one of the row attributes to determine which list to query and   //show in the current af:selectOneChoice list  // ...  ArrayList<SelectItem> alsi = new ArrayList<SelectItem>();  for( ... ){      SelectItem item = new SelectItem();        item.setLabel(...);        item.setValue(...);        alsi.add(item);   }   return alsi;} For better performance, the ADF Faces table stamps it data rows. Stamping means that the cell renderer component - af:selectOneChoice in this example - is instantiated once for the column and then repeatedly used to display the cell data for individual table rows. This however means that you cannot refresh a single select one choice component in a table to change its list values. Instead the whole table needs to be refreshed, rerunning the managed bean list query. Be aware that having individual list values per table row is an expensive operation that should be used only on small tables for Business Services with low latency data fetching (e.g. ADF Business Components and EJB) and with server side caching strategies for the queried data (e.g. storing queried list data in a managed bean in session scope).

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  • Project of Projects with team Foundation Server 2010

    - by Martin Hinshelwood
    It is pretty much accepted that you should use Areas instead of having many small Team Projects when you are using Team Foundation Server 2010. I have implemented this scenario many times and this is the current iteration of layout and considerations. If like me you work with many customers you will find that you get into a grove for how to set these things up to make them as easily understandable for everyone, while giving the best functionality. The trick is in making it as intuitive as possible for both you and the developers that need to work with it. There are five main places where you need to have the Product or Project name in prominence of any other value. Area Iteration Source Code Work Item Queries Build Once you decide how you are doing this in each of these places you need to keep to it religiously. Evan if you have one source code file to keep, make sure it is in the right place. This makes your developers and others working with the format familiar with where everything should go, as well as building up mussel memory. This prevents the neat system degenerating into a nasty mess. Areas Areas are traditionally used to separate out parts of your product / project so that you can see how much effort has gone into each. Figure: The top level areas are for reporting and work item separation There are massive advantages of using this method. You can: move work from one project to another rename a project / product It is far more likely that a project or product gets renamed than a department. Tip: If you have many projects, over 100, you should consider categorising them here, but make sure that the actual project name always sits at the same level so you know which is which. Figure: Always keep things that are the same at the same level Note: You may use these categories only at the Area/Iteration level to make it easier to select on drop down lists. You may not want to use them everywhere. On the other hand, for consistency it would be better to. Iterations Iterations are usually used to some sort of time based consideration. Here I am splitting into Iterations with periodic releases. Figure: Each product needs to be able to have its own cadence The ability to have each project run at its own pace and to enable them to have their own release schedule is often of paramount importance and you don’t want to fix your 100+ projects to all be released on the same date. Source Code Having a good structure for your source even if you are not branching or having multiple products under the same structure is always a good idea. Figure: Separate out your products source You need to think about both your branches as well as the structure of your source. All your code should be under “Source” and everything you need to build your solution including Build Scripts and 3rd party tools should be under your “Main” (branch) folder. This should them be branched by “Quality”, “Release” or both to get the most out of your branching structure. The important thing is to make sure you branch (or be able to branch) everything you need to build, test and deploy your application to an environment. That environment may be development, test or even production, but I can’t stress the importance of having everything your need. Note: You usually will not be able to install custom software on your build server. Store any *.dll’s or *.exe’s that you need under the “Tools\Tool1” folder. Note: Consult the Branching Guidance for Team Foundation Server 2010 for more on branching Figure: Adding category may be a necessary evil Even if you have to have a couple of categories called “Default”, it is better than not knowing the difference between a folder, Product and Branch. Work Item Queries Queries are used to load lists of Work Items out of TFS so you can see what work you have. This means that you want to also separate queries out by Product / project to make it easier to Figure: Again you have the same first level structure Having Folders also in Work Item Tracking we do the same thing. We put all the queries under a folder named for the Product / Project and change each query to have “AreaPath=[TeamProject]\[ProductX]” in the query instead of the standard “Project=@Project”. Tip: Don’t have a folder with new queries for each iteration. Instead have a single “Current” folder that has queries that point to the current iteration. Just change the queries as you move from one iteration to another. Tip: You can ctrl+drag the “Product1” folder to create your “Product2” folder. Builds You may have many builds both for individual products but also for different quality's. This can be further complicated by having some builds that action “Gated Check-In” and others that are specifically for “Release”, “Test” or another purpose. Figure: There are no folders, yet, for the builds so you need a good naming convention Its a pity that there are no folders under builds, some way to categorise would be nice. In lue of that at the moment you can use a functional naming convention that at least allows you to find what you want. Conclusion It is really easy to both achieve and to stick to this format if you take the time to do it. Unless you have 1000+ builds or 100+ Products you are unlikely run into any issues. Even then there are things you can do to mitigate the issues and I have describes some of them above. Let me know if you can think of any other things to make this easier.

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  • Which simple Java JPA ORM tool to use ?

    - by Guillaume
    What Java ORM library implementing JPA that match following criteria would you recommend and why ? free & open source alive (at least bug fixes and a mailing list) with good documentation simple (simpler than hibernate) I need to select a simple ORM tool that can be set up in minutes, without too much configuration and easy to understand, for setting simple CRUD DAOs. A query builder will be an interesting plus. Later I can have to move to Hibernate, that's why being JPA compliant is a must. I have found some candidates on the web, but not so much feedback, so I will gladly take your advices on the topic. ----- EDIT --------- I have been successfully testing ebean/avaje with a small test cases. Any one has a feedback on using these tools in production ?

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  • Would a model like this translate well to a document or graph database?

    - by Eric
    I'm trying to understand what types of models that I have traditionally persisted relationally would translate well to some kind of NoSQL database. Suppose I have a model with the following relationships: Product 1-----0..N Order Customer 1-----0..N Order And suppose I need to frequently query things like All Orders, All Products, All Customers, All Orders for Given Customer, All Orders for Given Product. My feeling is that this kind of model would not denormalize cleanly - If I had Product and Customer documents with embedded Orders, both documents would have duplicate orders. So I think I'd need separate documents for all three entities. Does a characteristic like this typically indicate that a document database is not well suited for a given model? Generally speaking, would a document database perform as well as a relational database in this kind of situation? I know very little about graph databases, but I understand that a graph database handles relationships more performantly than a document database - would a graph database be suited for this kind of model?

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  • New Endeca Commerce 3.1 Specialization Launched!

    - by Roxana Babiciu
    We’ve just launched the Endeca Commerce 3.1 Specialization! This is your chance to be recognized as a proficient Oracle partner in selling, implementing and/or developing Endeca Commerce 3.1 solutions.  Check the specialization criteria to make sure you qualify! Oracle partners who achieve this Specialization are differentiated in the marketplace through proven expertise in Oracle Endeca Commerce 3.1. Are you a member of the Endeca Community?  If not, this is the place to be for exchanging ideas and questions regarding Endeca Commerce use. Do check it out! Topics covered in the Specialization include: Application Configuration Record Design Pipeline Development Working with Search Features Experience Manager Concepts Overview of Query Types Application development with the Assembler API

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  • Unexpected advantage of Engineered Systems

    - by user12244672
    It's not surprising that Engineered Systems accelerate the debugging and resolution of customer issues. But what has surprised me is just how much faster issue resolution is with Engineered Systems such as SPARC SuperCluster. These are powerful, complex, systems used by customers wanting extreme database performance, app performance, and cost saving server consolidation. A SPARC SuperCluster consists or 2 or 4 powerful T4-4 compute nodes, 3 or 6 extreme performance Exadata Storage Cells, a ZFS Storage Appliance 7320 for general purpose storage, and ultra fast Infiniband switches.  Each with its own firmware. It runs Solaris 11, Solaris 10, 11gR2, LDoms virtualization, and Zones virtualization on the T4-4 compute nodes, a modified version of Solaris 11 in the ZFS Storage Appliance, a modified and highly tuned version of Oracle Linux running Exadata software on the Storage Cells, another Linux derivative in the Infiniband switches, etc. It has an Infiniband data network between the components, a 10Gb data network to the outside world, and a 1Gb management network. And customers can run whatever middleware and apps they want on it, clustered in whatever way they want. In one word, powerful.  In another, complex. The system is highly Engineered.  But it's designed to run general purpose applications. That is, the physical components, configuration, cabling, virtualization technologies, switches, firmware, Operating System versions, network protocols, tunables, etc. are all preset for optimum performance and robustness. That improves the customer experience as what the customer runs leverages our technical know-how and best practices and is what we've tested intensely within Oracle. It should also make debugging easier by fixing a large number of variables which would otherwise be in play if a customer or Systems Integrator had assembled such a complex system themselves from the constituent components.  For example, there's myriad network protocols which could be used with Infiniband.  Myriad ways the components could be interconnected, myriad tunable settings, etc. But what has really surprised me - and I've been working in this area for 15 years now - is just how much easier and faster Engineered Systems have made debugging and issue resolution. All those error opportunities for sub-optimal cabling, unusual network protocols, sub-optimal deployment of virtualization technologies, issues with 3rd party storage, issues with 3rd party multi-pathing products, etc., are simply taken out of the equation. All those error opportunities for making an issue unique to a particular set-up, the "why aren't we seeing this on any other system ?" type questions, the doubts, just go away when we or a customer discover an issue on an Engineered System. It enables a really honed response, getting to the root cause much, much faster than would otherwise be the case. Here's a couple of examples from the last month, one found in-house by my team, one found by a customer: Example 1: We found a node eviction issue running 11gR2 with Solaris 11 SRU 12 under extreme load on what we call our ExaLego test system (mimics an Exadata / SuperCluster 11gR2 Exadata Storage Cell set-up).  We quickly established that an enhancement in SRU12 enabled an 11gR2 process to query Infiniband's Subnet Manager, replacing a fallback mechanism it had used previously.  Under abnormally heavy load, the query could return results which were misinterpreted resulting in node eviction.  In several daily joint debugging sessions between the Solaris, Infiniband, and 11gR2 teams, the issue was fully root caused, evaluated, and a fix agreed upon.  That fix went back into all Solaris releases the following Monday.  From initial issue discovery to the fix being put back into all Solaris releases was just 10 days. Example 2: A customer reported sporadic performance degradation.  The reasons were unclear and the information sparse.  The SPARC SuperCluster Engineered Systems support teams which comprises both SPARC/Solaris and Database/Exadata experts worked to root cause the issue.  A number of contributing factors were discovered, including tunable parameters.  An intense collaborative investigation between the engineering teams identified the root cause to a CPU bound networking thread which was being starved of CPU cycles under extreme load.  Workarounds were identified.  Modifications have been put back into 11gR2 to alleviate the issue and a development project already underway within Solaris has been sped up to provide the final resolution on the Solaris side.  The fixed SPARC SuperCluster configuration greatly aided issue reproduction and dramatically sped up root cause analysis, allowing the correct workarounds and fixes to be identified, prioritized, and implemented.  The customer is now extremely happy with performance and robustness.  Since the configuration is common to other customers, the lessons learned are being proactively rolled out to other customers and incorporated into the installation procedures for future customers.  This effectively acts as a turbo-boost to performance and reliability for all SPARC SuperCluster customers.  If this had occurred in a "home grown" system of this complexity, I expect it would have taken at least 6 months to get to the bottom of the issue.  But because it was an Engineered System, known, understood, and qualified by both the Solaris and Database teams, we were able to collaborate closely to identify cause and effect and expedite a solution for the customer.  That is a key advantage of Engineered Systems which should not be underestimated.  Indeed, the initial issue mitigation on the Database side followed by final fix on the Solaris side, highlights the high degree of collaboration and excellent teamwork between the Oracle engineering teams.  It's a compelling advantage of the integrated Oracle Red Stack in general and Engineered Systems in particular.

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  • What ever happened to the Google AJAX Search API

    - by John
    I am looking to query the main Google search however all references including stackoveflow point to the Google AJAX Search API. The odd thing is that it does not seem to exist any more not even a note to say it is depreciated? The old links point to main Google code site. If I look at the list of API's on that site the API it replaced is there Web Search API (Deprecated) which links back to same page but not the Google AJAX Search API. Further Google searching is not being helpful either, many blog posts pointing to the same Google site (http://code.google.com/apis/ajaxsearch/) that has no content and redirects to the same place? Just to prove it did exist I have found it on the way back machine however the last snapshot did not show any special unusual message.

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  • Interview question: How would you implement Google Search?

    - by ripper234
    Supposed you were asked in an interview "How would you implement Google Search?" How would you answer such a question? There might be resources out there that explain how some pieces in Google are implemented (BigTable, MapReduce, PageRank, ...), but that doesn't exactly fit in an interview. What overall architecture would you use, and how would you explain this in a 15-30 minute time span? I would start with explaining how to build a search engine that handles ~ 100k documents, then expand this via sharding to around 50M docs, then perhaps another architectural/technical leap. This is the 20,000 feet view. What I'd like is the details - how you would actually answer that in an interview. Which data structures would you use. What services/machines is your architecture composed of. What would a typical query latency be? What about failover / split brain issues? Etc...

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  • At what size of data does it become beneficial to move from SQL to NoSQL?

    - by wobbily_col
    As a relational database programmer (most of the time), I read articles about how relational databases don't scale, and NoSQL solutions such as MongoDB do. As most of the databases I have developed so far have been small to mid scale, I have never had a problem that hasn't been solved by some indexing, query optimization or schema redesign. What sort of size would I expect to see MySQL struggling with. How many rows? (I know this is going to depend on the application, and type of data stored. the one that got me thing was basically a genetics database, so would have one main table, with 3 or 4 lookup tables. The main table will contain amongst other things, a chromosome reference, and a position coordinate. It will likely get queried for a number of entries between two potions on a chromosome, to see what is stored there).

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  • Structure of a correctly implemented JTable with TableModel and Listeners?

    - by bamboocha
    I am pretty new to Java and its JTables and this is where I am struggling at the moment. I need to create a GUI which shows me results of a sql query like SELECT * FROM tblPeople WHERE name='Doe'. My idea was to create a a JFrame which displays a JTable with all found records. Besides this, I need to also implement some code to handle when a user is double clicking a record or selecting it by using his arrow keys (additional feature: pressing 12(e.g.) should select the 12th record). What is the best way to structure my program (what classes do I need and especially where do I store my logic)? I came up with structuring it the following way: Main.java ("view") SQLConnection.java PeopleTableModel.java (only stores and returns data given by the passed ResultSet, "model" inherits from DefaultTableModel) PeopleTable.java (stores basically all my logic including KeyListener and MouseListener, "controller", inherits from JTable) Are there better ways to achieve my goals? If so, what are they?

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  • Discussion of a Distributed Data Storage implementation

    - by fegol
    I want to implement a distributed data storage using a client/server architecture. Each data item will be stored persistently in disk in one of several remote servers. The client uses a library to update and query the data, shielding the client from its actual location. This should allow a client to associate keys (String) to values(byte[]), much as a Map does. The system must ensure that the amount of data stored in each server is approximately the same. The set of servers is known beforehand by other servers and clients. Both the client and the server will be written in Java, using sockets, threads, and files. I open this topic with the objective of discussing the best way to implement this idea, assuming simplicity, what are the issues of this implementation, performance measurements and discussion of the limitations.

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