Search Results

Search found 4704 results on 189 pages for 'refactoring databases'.

Page 164/189 | < Previous Page | 160 161 162 163 164 165 166 167 168 169 170 171  | Next Page >

• Several Small, Specific, MySQL Query Cache Questions

  - by Robbie

  I've look all over the web and in the questions asked here about MySQL caching and most of them seem very non-specific about a couple of questions that I have about performance and MySQL query caching. Specifically I want answers to these questions, assume for all questions that I have the query cache enabled and it is of type 2, or "DEMAND": Is the query cache per table, per database, or per server? Meaning if I have the cache size set to X and have T tables and D databases will I be caching TX, DX, or X amount of data? If I have table T1 which I regularly use the SQL_CACHE hint on for SELECT queries and table T2 which I never do, when I query T2 with a SELECT query will it check through the cache first before performing the query? *Note: I don't want to use the SQL_NO_CACHE for all T2 queries.* Assume the same situation as in question 2. If I alter (INSERT, DELETE) table T2 will any processing be done on the cache? For answers to 2 and 3, is this processing time negligible if T2 is constantly being altered and is the target of a majority of my SELECT queries?

  Read the article

• What type of webapp is the sweet spot for Scala's Lift framework?

  - by ajay

  What kind of applications are the sweet spot for Scala's lift web framework. My requirements: Ease of development and maintainability Ready for production purposes. i.e. good active online community, regular patches and updates for security and performance fixes etc. Framework should survive a few years. I don't want to write a app in a framework for which no updates/patches are available after 1 year. Has good UI templating engines Interoperation with Java (Scala satisfies this arleady. Just mentioning here for completeness sake) Good component oriented development. Time required to develop should be proportion to the complexity of web application. Should not be totally configuration based. I hate it when code gets automatically generated for me and does all sorts of magic under the hood. That is a debugging nightmare. Amount of Lift knowledge required to develop a webapp should be proportional to the complexity of the web application. i.e I should't have to spend 10+ hours learning Lift just to develop a simple TODO application. (I have knowledge of Databases, Scala) Does Lift satisfy these requirements?

  Read the article

• Rails: constraint violation on create but not on update

  - by justinbach

  Note: This is a "railsier" (and more succinct) version of this question, which was getting a little long. I'm getting Rails behavior on a production server that I can't replicate on the development server. The codebases are identical save for credentials and caching settings, and both are powered by Oracle 10g databases with identical schema (but different data). My Rails application contains a user model, which has_one registration; registration in turn has_and_belongs_to_many company_ownerships through a registration_ownerships table. Upon registering, users fill out data pertinent to all three models, including a series of checkboxes indicating what registration_ownerships might apply to their account. On the dev server, the registration process is seamless, no matter what data is entered. On production, however, if users check off any of the company ownership fields before submitting their registration, Oracle complains about a constraint violation on the primary key of the company_ownerships table (which is a two-field key based on company_ownership_id and registration_id) and users get the standard Rails 500 error screen. In every case, I've verified that no conflicting record on these two fields exists in the production database, so I don't know why the constraint is getting violated. To further confuse things, if a user registers without listing any ownerships and later goes back and modifies their account to reflect ownership data (which is done through the same interface), the application happily complies with their request and Oracle is well-behaved (this is both on production and dev). I've spent the past couple days trying to figure out what might be causing this problem and am reaching the end of my wits. Any advice would be greatly appreciated!

  Read the article

• sql exception when transferring project from usb to c:\

  - by jello

  I'm working on a C# windows program with Visual Studio 2008. Usually, I work from school, directly on my usb drive. But when I copy the folder on my hard drive at home, an sql exception is unhandled whenever I try to write to the database. it is unhandled at the conn.Open(); line. here's the exception unhandled Database 'L:\system\project\the_project\the_project\bin\Debug\PatientMonitoringDatabase.mdf' already exists. Choose a different database name. Cannot attach the file 'C:\Documents and Settings\Administrator\My Documents\system\project\the_project\the_project\bin\Debug\PatientMonitoringDatabase.mdf' as database 'PatientMonitoringDatabase'. it's weird, because my connection string says |DataDirectory|, so it should work on any drive... here's my connection string: string connStr = "Data Source=.\\SQLEXPRESS;AttachDbFilename=|DataDirectory|\\PatientMonitoringDatabase.mdf; " + "Initial Catalog=PatientMonitoringDatabase; " + "Integrated Security=True"; Someone told me to: Connect to localhost with SQL Server Management Studio Express, and remove/detach the existing PatientMonitoringDatabase database. Whether it's a persistent database or only active within a running application, you can't have 2 databases with the same name at the same time attached to a SQL Server instance. So I did that, and now it gives me: Directory lookup for the file "C:\Documents and Settings\Administrator\My Documents\system\project\the_project\the_project\bin\Debug\PatientMonitoringDatabase.mdf" failed with the operating system error 5(Access is denied.). Cannot attach the file 'C:\Documents and Settings\Administrator\My Documents\system\project\the_project\the_project\bin\Debug\PatientMonitoringDatabase.mdf' as database 'PatientMonitoringDatabase' I checked the files' properties, and I have allow for everyone. Does anyone know what's going on here?

  Read the article

• Setting up a multi-site CMS, collecting thoughts about the DB schema

  - by Ben Fransen

  Hello all, I'm collecting some thoughts about creating a multisite CMS. In my opinion there are two major approaches. All data is stored into 1 database, giving me the advantage of single point of updates; Seperated databases, so each client has its own database. Giving me the advantage to measure bandwith. Option 1 gives me the disadvantage of measuring bandwith while option is giving me the disadvantage of a single point of update structure. Are there any generic approaches for creating a sort of update system? So my clients can download a small package (maybe a zip with a conf file to tell the updatescript where to put all the files and how to extend the database??) Do you guys have some thougths about the best solution for a situation like this? I have my own webserver, full access to all resources and I'm developing in PHP with MySQL as DBMS. I hope to hear from you and I surely appreciate any effort you make to help me further! Greets from Holland, Ben Fransen

  Read the article

• Parsing a blackberry .ipd file

  - by galaxywatcher

  I recently lost my Blackberry. When I discovered it was gone very shortly afterwards and called it, the sim card had already been removed. I ain't seeing that Blackberry again. Ok. I am out $300, but at least my data is backed up. I had an older working Blackberry fortunately and I got a new sim card and proceeded to restore my data using Blackberry Desktop Manager. 7000+ emails, hundreds of autotext entries, sms messages, calendar events, all backing up. Looking good. Lo and behold! My Address Book contacts refuse to back up? I try advanced, and it is greyed out as an option to restore. Far more frustrating than losing my bberry in the first place is wrangling with software that defies human logic. Ok, now I guess I will have to enter all 327 names by hand. That is, if I can read the .ipd file. I have tried the free version of ABC Amber Blackberry editor, but when I open the .ipd file, the contacts just do not show up. I am beginning to feel like the gods are conspiring against me. Then I found this: http://jabide.com/2009/03/parse-blackberry-ipd-files/ He posted a perl script that claims to extract the files. I copied and pasted the code and it did list all the different databases in my .ipd file, I was elated that a cool solution like this was published. I followed the instructions and garbled data with some discernible ascii was sent to standard output unlike a .csv file like he said it would. This is enough to make a grown man cry. Does anyone out there have a solution to extract my address book contacts from an .ipd file?

  Read the article

• How do you deal with denormalization / secondary indexes in database sharding?

  - by Continuation

  Say I have a "message" table with 2 secondary indexes: "recipient_id" "sender_id" I want to shard the "message" table by "recipient_id". That way to retrieve all messages sent to a certain recipient I only need to query one shard. But at the same time, I want to be able to make a query that ask for all messages sent by a certain sender. Now I don't want to send that query to every single shard of the "message" table. One way to do this is to duplicate the data and have a "message_by_sender" table sharded by "sender_id". The problem with that approach is that every time a message has been sent, I need to insert the message into both "message" and "message_by_sender" tables. But what if after inserting into "message" the insertion into "message_by_sender" fail? In that case the message exists in "message" but not in "message_by_sender". How do I make sure that if a message exists in "message" then it also exists in "message_by_sender" without resorting to 2 phase commit? This must be a very common issue for anyone who shards their databases. How do you deal woth it?

  Read the article

• What's the largest (most complex) PHP algorithm ever implemented in a single monolithic PHP script?

  - by Alex R

  I'm working on a tool which converts PHP code to Scala. As one of the finishing touches, I'm in need of a really good (er, somewhat biased) benchmark. By dumb luck my first benchmark attempt was with some code which uses bcmath extensively, which unfortunately is 1000x slower in Java, making the Scala code 22x slower overall than the original PHP. So I'm looking for some meaningful PHP benchmark with the following characteristics: The source needs to be in a single file. I need it to be simple to setup - no databases, hard-to-find input files, etc. Simple text input and output preferred. It should not use features that are slow in Java (BigInteger, trigonometric functions, etc). It should not use exoteric or dynamic PHP functions (e.g. no "eval" or "variable vars"). It should not over-rely on built-in libraries, e.g. MD5, crypt, etc. It should not be I/O bound. A CPU-bound memory-hungry algorithm is preferred. Basically, intensive OO operations, integer and string manipulation, recursion, etc would be great. Thanks

  Read the article

• Beginner SQL question: querying gold and silver tag badges in Stack Exchange Data Explorer

  - by polygenelubricants

  I'm using the Stack Exchange Data Explorer to learn SQL, but I think the fundamentals of the question is applicable to other databases. I'm trying to query the Badges table, which according to Stexdex (that's what I'm going to call it from now on) has the following schema: Badges Id UserId Name Date This works well for badges like [Epic] and [Legendary] which have unique names, but the silver and gold tag-specific badges seems to be mixed in together by having the same exact name. Here's an example query I wrote for [mysql] tag: SELECT UserId as [User Link], Date FROM Badges Where Name = 'mysql' Order By Date ASC The (slightly annotated) output is: as seen on stexdex: User Link Date --------------- ------------------- // all for silver except where noted Bill Karwin 2009-02-20 11:00:25 Quassnoi 2009-06-01 10:00:16 Greg 2009-10-22 10:00:25 Quassnoi 2009-10-31 10:00:24 // for gold Bill Karwin 2009-11-23 11:00:30 // for gold cletus 2010-01-01 11:00:23 OMG Ponies 2010-01-03 11:00:48 Pascal MARTIN 2010-02-17 11:00:29 Mark Byers 2010-04-07 10:00:35 Daniel Vassallo 2010-05-14 10:00:38 This is consistent with the current list of silver and gold earners at the moment of this writing, but to speak in more timeless terms, as of the end of May 2010 only 2 users have earned the gold [mysql] tag: Quassnoi and Bill Karwin, as evidenced in the above result by their names being the only ones that appear twice. So this is the way I understand it: The first time an Id appears (in chronological order) is for the silver badge The second time is for the gold Now, the above result mixes the silver and gold entries together. My questions are: Is this a typical design, or are there much friendlier schema/normalization/whatever you call it? In the current design, how would you query the silver and gold badges separately? GROUP BY Id and picking the min/max or first/second by the Date somehow? How can you write a query that lists all the silver badges first then all the gold badges next? Imagine also that the "real" query may be more complicated, i.e. not just listing by date. How would you write it so that it doesn't have too many repetition between the silver and gold subqueries? Is it perhaps more typical to do two totally separate queries instead? What is this idiom called? A row "partitioning" query to put them into "buckets" or something?

  Read the article

• Execute SQL on CSV files via JDBC

  - by Markos Fragkakis

  Dear all, I need to apply an SQL query to CSV files (comma-separated text files). My SQL is predefined from another tool, and is not eligible to change. It may contain embedded selects and table aliases in the FROM part. For my task I have found two open-source (this is a project requirement) libraries that provide JDBC drivers: CsvJdbc XlSQL JBoss Teiid Create an Apache Derby DB, load all CSVs as tables and execute the query. These are the problems I encountered: it does not accept the syntax of the SQL (it uses internal selects and table aliases). Furthermore, it has not been maintained since 2004. I could not get it to work, as it has as dependency a SAX Parser that causes exception when parsing other documents. Similarly, no change since 2004. Have not checked if it supports the syntax, but seems like an overhead. It needs several entities defines (Virtual Databases, Bindings). From the mailing list they told me that last release supports runtime creation of required objects. Has anyone used it for such simple task (normally it can connect to several types of data, like CSV, XML or other DBS and create a virtual, unified one)? Can this even be done easily? From the 4 things I considered/tried, only 3 and 4 seem to me viable. Any advice on these, or any other way in which I can query my CSV files? Cheers

  Read the article

• iPhone and Core Data: how to retain user-entered data between updates?

  - by Shaggy Frog

  Consider an iPhone application that is a catalogue of animals. The application should allow the user to add custom information for each animal -- let's say a rating (on a scale of 1 to 5), as well as some notes they can enter in about the animal. However, the user won't be able to modify the animal data itself. Assume that when the application gets updated, it should be easy for the (static) catalogue part to change, but we'd like the (dynamic) custom user information part to be retained between updates, so the user doesn't lose any of their custom information. We'd probably want to use Core Data to build this app. Let's also say that we have a previous process already in place to read in animal data to pre-populate the backing (SQLite) store that Core Data uses. We can embed this database file into the application bundle itself, since it doesn't get modified. When a user downloads an update to the application, the new version will include the latest (static) animal catalogue database, so we don't ever have to worry about it being out of date. But, now the tricky part: how do we store the (dynamic) user custom data in a sound manner? My first thought is that the (dynamic) database should be stored in the Documents directory for the app, so application updates don't clobber the existing data. Am I correct? My second thought is that since the (dynamic) user custom data database is not in the same store as the (static) animal catalogue, we can't naively make a relationship between the Rating and the Notes entities (in one database) and the Animal entity (in the other database). In this case, I would imagine one solution would be to have an "animalName" string property in the Rating/Notes entity, and match it up at runtime. Is this the best way to do it, or is there a way to "sync" two different databases in Core Data?

  Read the article

• A business Case for Enterprise Python

  - by Srirangan

  Hi all, This will not be a "programming" question but more technology / platform related question. I'm trying to figure out whether Python can be a suitable Java alternative for enterprise / web applications. Which are the ideal cases where you would prefer to use Python instead of Java? How would a typical Python web application (databases/sessions/concurrency) perform as compared to a typical Java application? How do specific Python frameworks square up against Java based frameworks (Spring, SEAM, Grails etc.)? For businesses, switching from the Java infrastructure to a Python infrastructure .. is it too hard/expensive/resource intensive/not viable? Also shed some light on the business case for providing a Python + Google AppEngine based solution to the end customer. Will it be cost effective in an typical scenario? Sorry if I am asking too wide a question, I would have liked to keep it specific, but I need your help to evaluate Python as a whole from the perspectives of the programmers, service providing company and end business customer. For an SME, a Python/GoogleAppEngine based technology stack is a clear scalable and affordable platform. But what about a large MNC that already has a lot invested in Java. Thank you so much. I am researching this myself and will gladly share my conclusions here! Thank you, Srirangan

  Read the article

• Handling dependencies with IoC that change within a single function call

  - by Jess

  We are trying to figure out how to setup Dependency Injection for situations where service classes can have different dependencies based on how they are used. In our specific case, we have a web app where 95% of the time the connection string is the same for the entire Request (this is a web application), but sometimes it can change. For example, we might have 2 classes with the following dependencies (simplified version - service actually has 4 dependencies): public LoginService (IUserRepository userRep) { } public UserRepository (IContext dbContext) { } In our IoC container, most of our dependencies are auto-wired except the Context for which I have something like this (not actual code, it's from memory ... this is StructureMap): x.ForRequestedType().Use() .WithCtorArg("connectionString").EqualTo(Session["ConnString"]); For 95% of our web application, this works perfectly. However, we have some admin-type functions that must operate across thousands of databases (one per client). Basically, we'd want to do this: public CreateUserList(IList<string> connStrings) { foreach (connString in connStrings) { //first create dependency graph using new connection string ???? //then call service method on new database _loginService.GetReportDataForAllUsers(); } } My question is: How do we create that new dependency graph for each time through the loop, while maintaining something that can easily be tested?

  Read the article

• How to avoid chaotic ASP.NET web application deployment?

  - by emzero

  Ok, so here's the thing. I'm developing an existing (it started being an ASP classic app, so you can imagine :P) web application under ASP.NET 4.0 and SQLServer 2005. We are 4 developers using local instances of SQL Server 2005 Express, having the source-code and the Visual Studio database project This webapp has several "universes" (that's how we call it). Every universe has its own database (currently on the same server) but they all share the same schema (tables, sprocs, etc) and the same source/site code. So manually deploying is really annoying, because I have to deploy the source code and then run the sql scripts manually on each database. I know that manual deploying can cause problems, so I'm looking for a way of automating it. We've recently created a Visual Studio Database Project to manage the schema and generate the diff-schema scripts with different targets. I don't have idea how to put the pieces together I would like to: Have a way to make a "sync" deploy to a target server (thanksfully I have full RDC access to the servers so I can install things if required). With "sync" deploy I mean that I don't want to fully deploy the whole application, because it has lots of files and I just want to deploy those new or changed. Generate diff-sql update scripts for every database target and combine it to just 1 script. For this I should have some list of the databases names somewhere. Copy the site files and executing the generated sql script in an easy and automated way. I've read about MSBuild, MS WebDeploy, NAnt, etc. But I don't really know where to start and I really want to get rid of this manual deploy. If there is a better and easier way of doing it than what I enumerated, I'll be pleased to read your option. I know this is not a very specific question but I've googled a lot about it and it seems I cannot figure out how to do it. I've never used any automation tool to deploy. Any help will be really appreciated, Thank you all, Regards

  Read the article

• Multiple database with NHibernate

  - by Flint

  Hi, I have two databases. One from Oracle 10g. Another from Mysql. I have configured my web application with Nhibernate for Oracle and now I am in need of using the MySQL database. So how can i configure the hibernate.cfg.xml so that i can use both of the database at the same application? My current hibernate.cfg.xml is: <?xml version="1.0" encoding="utf-8" ?> <hibernate-configuration xmlns="urn:nhibernate-configuration-2.2"> <session-factory> <property name="connection.provider">NHibernate.Connection.DriverConnectionProvider</property> <property name="connection.driver_class">NHibernate.Driver.OracleClientDriver</property> <property name="connection.connection_string">Data Source=xe;Persist Security Info=True;User ID=hr;Password=hr;Unicode=True</property> <property name="show_sql">false</property> <property name="dialect">NHibernate.Dialect.Oracle9Dialect</property> <!-- mapping files --> <mapping assembly="DataTransfer" /> </session-factory> </hibernate-configuration>

  Read the article

• Getting content from PHP: Trouble with POST and query.

  - by vgm64

  Apologies for my longest question on SO ever. I'm trying to interface with a php frontend for a mysql database in ROOT (a CERN framework in C++ for high energy physics analysis). To start off with, I tried to get this php interface to play nice with wget and curl first because I'm more familiar with them. The following command works: wget --post-data "hostname=localhost:3306&un=joeuser&pw=psswd&myquery=show_spazio_databases;" http://some.host.edu/log/log_query_matlab.php The results are: database1 database2 That's good. If I leave out the --post-data then I get the result: Warning: mysql_connect() [function.mysql-connect]: Access denied for user 'admin'@'localhost' (using password: NO) in /log/log_query_matlab.php on line 6 i'm dead! Access denied for user 'admin'@'localhost' (using password: NO) Warning: mysql_query() [function.mysql-query]: Access denied for user 'admin'@'localhost' (using password: NO) in /log/log_query_matlab.php on line 29 Warning: mysql_query() [function.mysql-query]: A link to the server could not be established in /log/log_query_matlab.php on line 29 I have access to the php script (read only), but the error itself isn't too important. What matters it that using ROOT, I use a function called as socket.SendRaw(message, message.Length()) (socket is a TSocket) and this gives me the same "error" as wget without the post data switch if my "message" is "POST http://some.host.edu/log/log_query_matlab.php?hostname=localhost:3306&un=joeuser&pw=psswd&myquery=show_spazio_databases" This may be in vain, but does someone knows a way I should format the "message" that includes something that is equivalent to the --post-data switch. Or, is there a standard way to format POST requests in a single line (I've seen multi-line stuff. Is that right?) Sorry I'm clueless! PS. The mysql query is show databases but the space has been replaced with _spazio_, Italian for space. The author of the db and php interface requires it (and various replacements for symbols), but has anyone seen this before? Trying to troubleshoot that was terrible!

  Read the article

• Which PHP library I should choose to work with CouchDB?

  - by Guss

  I want to try playing with CouchDB for a new project I'm writing (as a hobby, not part of my job). I'm well versed in PHP, but I haven't programmed with CouchDB at all, and also I have little experience with non-SQL databases. From looking at CouchDB's "Getting Started with PHP" document they recommend using a third-party library or writing your own client using their RESTful HTTP API. I think I'd rather not mess with writing protocol implementations myself at this point, but what is your experience with writing PHP to work with CouchDB? I haven't tested any of the alternatives yet, but I looked at: PHPillow : I'm interested in the way they implement ORM. I wasn't planning to do ORM, but my problem domain probably map well to that method. PHP Object Freezer: seems like a poor man's ORM - I can use it to implement an actual ORM, or just as an easy store/retrieve document API but it seems too primitive. PHP-on-Couch : Also a bit simple, but they have an interesting API for views and from the documentation it looks usable enough. PHP CouchDB Extension : From the listed options this looks like it has the best chance of making it into the PHP mainline itself, and also has the most complete API. Any opinion one wish to share on each library is welcome.

  Read the article

• Running SQLite 3 in MicroApache

  - by Alien426

  I'm running MicroApache (http://microapache.amadis.sytes.net) on Windows XP and would like to use SQLite 3 databases. The PHP version is 5.2.9-2. My MicroApache version has SQLite 2 support through 2 lines in the php.ini: extension=php_pdo.dll extension=php_sqlite.dll I test whether the extension works in 3 ways: 1. phpinfo() 2. extension_loaded() and get_loaded_extensions() 3. using sample code that var_dump()s the constant SQLITE3_NUM (should be the integer 2) and tries to create a database (error: class 'SQLite3' does not exist) Things I have tried (if I can remember them all): 1. copied php_sqlite3.dll from a full installation of PHP and added "extension=php_sqlite3.dll" to php.ini - error "Procedure entry point gc_remove_zval_from_buffer was not found in php5ts.dll" 2. compressed the DLL with UPX (like the other DLLs of MicroApache seem to be) - does not display an error on start, nor in the log file, but does not work 3. tried various things with php.ini - created a section "[sqlite3]" - prefixed "sqlite3." to "extension_dir=." and "extension=php_sqlite3.dll" - ... 4. tried to use PDO, it says it 'could not find driver' Who can help me get SQLite 3 to work?

  Read the article

• Splitting MS Access Database - Front End Part Location

  - by kristof

  One of the best practices as specified by Microsoft for Access Development is splitting Access application into 2 parts; Front End that hold all the object except tables and the Back End that holds the tables. The msdn page links there to the article Splitting Microsoft Access Databases to Improve Performance and Simplify Maintainability that describes the process in details. It is recommended that in multi user environment the Back End is stored on the server/shared folder while the Front End is distributed to each user. That implies that each time there are any changes made to the front end they need to be deployed to every user machine. My question is: Assuming that the users themselves do not have rights to modify the Front End part of the application what would be the drawbacks/dangers of leaving this on the server as well next to the Back End copy? I can see the performance issues here, but are there any dangers here like possible corruptions etc? Thank you EDIT Just to clarify, the scenario specified in question assumes one Front End stored on the server and shared by users. I understand that the recommendation is to have FE deployed to each user machine, but my question is more about what are the dangers if that is not done. E.g. when you are given an existing solution that uses the approach of both FE and BE on the server. Assuming the the performance is acceptable and the customer is reluctant to change the approach would you still push the change? And why exactly? For example the danger of possible data corruption would definitely be the strong enough argument, but is that the case? It is a part of follow up of my previous question From SQL Server to MS Access 2007

  Read the article

• Combining data sets without losing observations in SAS

  - by John

  Hye guys, I know, another post another problem :D :(. I took a screenshot to easily explain my problem. http://i39.tinypic.com/rhms0h.jpg As you can see I want to merge two tables (again), the Base & Analyst table. What I want to achieve is displayed in the right bottom corner table. I’m calculating the number of total analysts and female analysts for each month in the analyst table. In the base table I have different observations for one company (here company Alcoa with ticker AA). When I use the following command: data want; merge base analyst; by month ; run; I get the right up corner problem. My observations in the main table are being narrowed down to only 4 observations (for each different year one observation, 2001, 2002, 2005, 2006). What I want is that the observations are not reduced but that for every year the same data is being placed as shown in the right bottom corner. What am I missing in my merge command? In both tables I have month as a time count variable ( the observations in my base table are monthly) on which I need to merge. For clarity I added 2 screenshots of my real databases in SAS. The base table: http://i42.tinypic.com/dr5jky.jpg The analyst table: http://i40.tinypic.com/eqpmqq.jpg Here is what my merged table looks like: http://i43.tinypic.com/116i62s.jpg You can clearly see that the merged table only has four observations left for AA (one for each unique year) instead of the original 8. Anyone an idea to solve this?

  Read the article

• Is there a PHP benchmark that meets these specific criteria? [closed]

  - by Alex R

  I'm working on a tool which converts PHP code to Scala. As one of the finishing touches, I'm in need of a really good (er, somewhat biased) benchmark. By dumb luck my first benchmark attempt was with some code which uses bcmath extensively, which unfortunately is 1000x slower in Java, making the Scala code 22x slower overall than the original PHP. So I'm looking for some meaningful PHP benchmark with the following characteristics: The PHP source needs to be in a single file. It should solve a real-world problem. No silly looping over empty methods etc. I need it to be simple to setup - no databases, hard-to-find input files, etc. Simple text input and output preferred. It should not use features that are slow in Java (BigInteger, trigonometric functions, etc). It should not use exoteric or dynamic PHP functions (e.g. no "eval" or "variable vars"). It should not over-rely on built-in libraries, e.g. MD5, crypt, etc. It should not be I/O bound. A CPU-bound memory-hungry algorithm is preferred. Basically, intensive OO operations, integer and string manipulation, recursion, etc would be great. Thanks

  Read the article

• Advice on designing and building distributed application to track vehicles

  - by dario-g

  I'm working on application for tracking vehicles. There will be about 10k or more vehicles. Each will be sending ~250bytes in each minute. Data contains gps location and everything from CAN Bus (every data that we can read from vehicle computer and dashboard). Data are sent by GSM/GPRS (using UDP protocol). Estimated rows with this data per day is ~2000k. I see there 3 main blocks. 1. Multithreaded Socket Server (MSS) - I have it. MSS stores received data to the queue (using NServiceBus). 2. Rule Processor Server (RPS) - this is core of this system. This block is responsible for parsing received data, storing in the database, processing rules, sending messages to Notifier Server (this will be sending e-mails/sms texts). Rule example. As I said between received bytes there will be information about current speed. When speed will be above 120 then: show alert in web application for specified users, send e-mail, send sms text. (There can be more than one instance of RPS). 3. Web application - allows reporting and defining rules by users, monitoring alerts, etc. I'm looking for advice how to design communication between RPS and Web application. Some questions: - Should Web application and RPS have separated databases or one central database will be enough? I have one domain model in web application. If there will be one central database then can I use the same model (objects) on RPS? So, how to send changed rules to RPS? I try to decouple this blocks as much as possible. I'm planning to create different instance of application for each client (each client will have separated database). One client will be have 10k vehicles, others only 100 vehicles.

  Read the article

• Is it just me? I find LINQ to XML to be sort of cumbersome, compared to XPath.

  - by Cheeso

  I am a C# programmer, so I don't get to take advantage of the cool XML syntax in VB. Dim itemList1 = From item In rss.<rss>.<channel>.<item> _ Where item.<description>.Value.Contains("LINQ") Or _ item.<title>.Value.Contains("LINQ") Using C#, I find XPath to be easier to think about, easier to code, easier to understand, than performing a multi-nested select using LINQ to XML. Look at this syntax, it looks like Greek swearing: var waypoints = from waypoint in gpxDoc.Descendants(gpx + "wpt") select new { Latitude = waypoint.Attribute("lat").Value, Longitude = waypoint.Attribute("lon").Value, Elevation = waypoint.Element(gpx + "ele") != null ? waypoint.Element(gpx + "ele").Value : null, Name = waypoint.Element(gpx + "name") != null ? waypoint.Element(gpx + "name").Value : null, Dt = waypoint.Element(gpx + "cmt") != null ? waypoint.Element(gpx + "cmt").Value : null }; All the casting, the heavy syntax, the possibility for NullPointerExceptions. None of this happens with XPath. I like LINQ in general, and I use it on object collections and databases, but my first go-round with querying XML led me right back to XPath. Is it just me? Am I missing something? EDIT: someone voted to close this as "not a real question". But it is a real question, stated clearly. The question is: Am I misunderstanding something with LINQ to XML?

  Read the article

• exec problem in sql 2005

  - by IordanTanev

  Hi, i have the situation where i have two databases whith same structure. The first have some data in its datatables. I need to create a script that will transfer the data from the first database to the second. I have created this script. DECLARE @table_name nvarchar(MAX), @query nvarchar(MAX) DECLARE @table_cursor CURSOR SET @table_cursor = CURSOR FAST_FORWARD FOR Select TABLE_NAME FROM INFORMATION_SCHEMA.TABLES OPEN @table_cursor FETCH NEXT FROM @table_cursor INTO @table_name WHILE @@FETCH_STATUS = 0 BEGIN SET @query = 'INSERT INTO ' + @table_name + ' SELECT * FROM MyDataBase.dbo.' + @table_name print @query exec @query FETCH NEXT FROM @table_cursor INTO @table_name END CLOSE @table_cursor DEALLOCATE @table_cursor The problem is that when i run th script the "print @query" statement prints statement like this INSERT INTO table SELECT * FROM MyDataBase.dbo.table When i copy this and run it from Management studio it works fine. But when the script trys to run it with exec i get this error Msg 911, Level 16, State 1, Line 21 Could not locate entry in sysdatabases for database 'INSERT INTO table SELECT * FROM MPDEV090314'. No entry found with that name. Make sure that the name is entered correctly. Hope someone can tell me whot is wront with this. Best Regards, Iordan Tanev

  Read the article

• Database Error Handling: What if You have to Call Outside service and the Transaction Fails?

  - by Ngu Soon Hui

  We all know that we can always wrap our database call in transaction ( with or without a proper ORM), in a form like this: $con = Propel::getConnection(EventPeer::DATABASE_NAME); try { $con->begin(); // do your update, save, delete or whatever here. $con->commit(); } catch (PropelException $e) { $con->rollback(); throw $e; } This way would guarantee that if the transaction fails, the database is restored to the correct status. But the problem is that let's say when I do a transaction, in addition to that transaction, I need to update another database ( an example would be when I update an entry in a column in databaseA, another entry in a column in databaseB must be updated). How to handle this case? Let's say, this is my code, I have three databases that need to be updated ( dbA, dbB, dbc): $con = Propel::getConnection("dbA"); try { $con->begin(); // update to dbA // update to dbB //update to dbc $con->commit(); } catch (PropelException $e) { $con->rollback(); throw $e; } If dbc fails, I can rollback the dbA but I can't rollback dbb. I think this problem should be database independent. And since I am using ORM, this should be ORM independent as well. Update: Some of the database transactions are wrapped in ORM, some are using naked PDO, oledb ( or whatever bare minimum language provided database calls). So my solution has to take care this. Any idea?

  Read the article

< Previous Page | 160 161 162 163 164 165 166 167 168 169 170 171  | Next Page >