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• How to map one class against multiple tables with SQLAlchemy?

  - by tote

  Lets say that I have a database structure with three tables that look like this: items - item_id - item_handle attributes - attribute_id - attribute_name item_attributes - item_attribute_id - item_id - attribute_id - attribute_value I would like to be able to do this in SQLAlchemy: item = Item('item1') item.foo = 'bar' session.add(item) session.commit() item1 = session.query(Item).filter_by(handle='item1').one() print item1.foo # => 'bar' I'm new to SQLAlchemy and I found this in the documentation (http://www.sqlalchemy.org/docs/05/mappers.html#mapping-a-class-against-multiple-tables): j = join(items, item_attributes, items.c.item_id == item_attributes.c.item_id). \ join(attributes, item_attributes.c.attribute_id == attributes.c.attribute_id) mapper(Item, j, properties={ 'item_id': [items.c.item_id, item_attributes.c.item_id], 'attribute_id': [item_attributes.c.attribute_id, attributes.c.attribute_id], }) It only adds item_id and attribute_id to Item and its not possible to add attributes to Item object. Is what I'm trying to achieve possible with SQLAlchemy? Is there a better way to structure the database to get the same behaviour of "dynamic columns"?

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• How to store opening weekdays in a database

  - by JoaoPedro

  I have a group of checkboxes where the user selects some of the weekdays (the opening days of a store). How can I save the selected days? Should I save something like 0111111 (zero means closed on sunday) on the same field and split the result when reading the data? Or create a field for each day and store 0 or 1 on each (weird)?

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• How to retrieve items from a database c#

  - by Poppy

  I have 3 tables "pics", "shows", "showpics" I want to be able to edit the table "shows". In order to do this i need to retrive the pictures that the show contains (the pictures are stored in the table "pics") the "showpics" table acts as a link does anyone have any ideas as im completely lost and have no idea where to even start Thanks

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• What kind of database to use in C#

  - by Chris

  I'm writing a program in C# that will need to store a few Data Tables on the user's computer and load them back when he restarts the program: Up to about 10000 records consisting of text and integers. I don't want to use a CSV file, and I had some trouble with SQLite. Are there any other good options to try?

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• What kind of database to use in .NET

  - by Chris

  I'm writing a program in C# that will need to store a few Data Tables on the user's computer and load them back when he restarts the program: Up to about 10000 records consisting of text and integers. I don't want to use a CSV file, and I had some trouble with SQLite. Are there any other good options to try?

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• SQLite - executeUpdate exception not caught when database does not exist? (Java)

  - by giant91

  So I was purposely trying to break my program, and I've succeeded. I deleted the sqlite database the program uses, while the program was running, after I already created the connection. Then I attempted to update the database as seen below. Statement stmt; try { stmt = Foo.con.createStatement(); stmt.executeUpdate("INSERT INTO "+table+" VALUES (\'" + itemToAdd + "\')"); } catch(SQLException e) { System.out.println("Error: " + e.toString()); } The problem is, it didn't catch the exception, and continued to run as if the database was updated successfully. Meanwhile the database didn't even exist at that point since this was after I deleted it. Doesn't it check if the database still exists when updating? Do I have to check the database connection manually, every time I update to ensure that the database wasn't corrupted/deleted? Is this the way it is normally done, or is there a simpler/more robust approach? Thank you.

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• Is this distributed database server idea feasible?

  - by David

  I often use SQLite for creating simple programs in companies. The database is placed on a file server. This works fine as long as there are not more than about 50 users working towards the database concurrently (though depending on whether it is reads or writes). Once there are more than this, they will notice a slowdown if there are a lot of concurrent writing on the server as lots of time is spent on locks, and there is nothing like a cache as there is no database server. The advantage of not needing a database server is that the time to set up something like a company Wiki or similar can be reduced from several months to just days. It often takes several months because some IT-department needs to order the server and it needs to conform with the company policies and security rules and it needs to be placed on the outsourced server hosting facility, which screws up and places it in the wrong localtion etc. etc. Therefore, I thought of an idea to create a distributed database server. The process would be as follows: A user on a company computer edits something on a Wiki page (which uses this database as its backend), to do this he reads a file on the local harddisk stating the ip-address of the last desktop computer to be a database server. He then tries to contact this computer directly via TCP/IP. If it does not answer, then he will read a file on the file server stating the ip-address of the last desktop computer to be a database server. If this server does not answer either, his own desktop computer will become the database server and register its ip-address in the same file. The SQL update statement can then be executed, and other desktop computers can connect to his directly. The point with this architecture is that, the higher load, the better it will function, as each desktop computer will always know the ip-address of the database server. Also, using this setup, I believe that a database placed on a fileserver could serve hundreds of desktop computers instead of the current 50 or so. I also do not believe that the load on the single desktop computer, which has become database server will ever be noticable, as there will be no hard disk operations on this desktop, only on the file server. Is this idea feasible? Does it already exist? What kind of database could support such an architecture?

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• Using jQuery to Insert a New Database Record

  - by Stephen Walther

  The goal of this blog entry is to explore the easiest way of inserting a new record into a database using jQuery and .NET. I’m going to explore two approaches: using Generic Handlers and using a WCF service (In a future blog entry I’ll take a look at OData and WCF Data Services). Create the ASP.NET Project I’ll start by creating a new empty ASP.NET application with Visual Studio 2010. Select the menu option File, New Project and select the ASP.NET Empty Web Application project template. Setup the Database and Data Model I’ll use my standard MoviesDB.mdf movies database. This database contains one table named Movies that looks like this: I’ll use the ADO.NET Entity Framework to represent my database data: Select the menu option Project, Add New Item and select the ADO.NET Entity Data Model project item. Name the data model MoviesDB.edmx and click the Add button. In the Choose Model Contents step, select Generate from database and click the Next button. In the Choose Your Data Connection step, leave all of the defaults and click the Next button. In the Choose Your Data Objects step, select the Movies table and click the Finish button. Unfortunately, Visual Studio 2010 cannot spell movie correctly :) You need to click on Movy and change the name of the class to Movie. In the Properties window, change the Entity Set Name to Movies. Using a Generic Handler In this section, we’ll use jQuery with an ASP.NET generic handler to insert a new record into the database. A generic handler is similar to an ASP.NET page, but it does not have any of the overhead. It consists of one method named ProcessRequest(). Select the menu option Project, Add New Item and select the Generic Handler project item. Name your new generic handler InsertMovie.ashx and click the Add button. Modify your handler so it looks like Listing 1: Listing 1 – InsertMovie.ashx using System.Web; namespace WebApplication1 { /// <summary> /// Inserts a new movie into the database /// </summary> public class InsertMovie : IHttpHandler { private MoviesDBEntities _dataContext = new MoviesDBEntities(); public void ProcessRequest(HttpContext context) { context.Response.ContentType = "text/plain"; // Extract form fields var title = context.Request["title"]; var director = context.Request["director"]; // Create movie to insert var movieToInsert = new Movie { Title = title, Director = director }; // Save new movie to DB _dataContext.AddToMovies(movieToInsert); _dataContext.SaveChanges(); // Return success context.Response.Write("success"); } public bool IsReusable { get { return true; } } } } In Listing 1, the ProcessRequest() method is used to retrieve a title and director from form parameters. Next, a new Movie is created with the form values. Finally, the new movie is saved to the database and the string “success” is returned. Using jQuery with the Generic Handler We can call the InsertMovie.ashx generic handler from jQuery by using the standard jQuery post() method. The following HTML page illustrates how you can retrieve form field values and post the values to the generic handler: Listing 2 – Default.htm <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title>Add Movie</title> <script src="http://ajax.microsoft.com/ajax/jquery/jquery-1.4.2.js" type="text/javascript"></script> </head> <body> <form> <label>Title:</label> <input name="title" /> <br /> <label>Director:</label> <input name="director" /> </form> <button id="btnAdd">Add Movie</button> <script type="text/javascript"> $("#btnAdd").click(function () { $.post("InsertMovie.ashx", $("form").serialize(), insertCallback); }); function insertCallback(result) { if (result == "success") { alert("Movie added!"); } else { alert("Could not add movie!"); } } </script> </body> </html>     When you open the page in Listing 2 in a web browser, you get a simple HTML form: Notice that the page in Listing 2 includes the jQuery library. The jQuery library is included with the following SCRIPT tag: <script src="http://ajax.microsoft.com/ajax/jquery/jquery-1.4.2.js" type="text/javascript"></script> The jQuery library is included on the Microsoft Ajax CDN so you can always easily include the jQuery library in your applications. You can learn more about the CDN at this website: http://www.asp.net/ajaxLibrary/cdn.ashx When you click the Add Movie button, the jQuery post() method is called to post the form data to the InsertMovie.ashx generic handler. Notice that the form values are serialized into a URL encoded string by calling the jQuery serialize() method. The serialize() method uses the name attribute of form fields and not the id attribute. Notes on this Approach This is a very low-level approach to interacting with .NET through jQuery – but it is simple and it works! And, you don’t need to use any JavaScript libraries in addition to the jQuery library to use this approach. The signature for the jQuery post() callback method looks like this: callback(data, textStatus, XmlHttpRequest) The second parameter, textStatus, returns the HTTP status code from the server. I tried returning different status codes from the generic handler with an eye towards implementing server validation by returning a status code such as 400 Bad Request when validation fails (see http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html ). I finally figured out that the callback is not invoked when the textStatus has any value other than “success”. Using a WCF Service As an alternative to posting to a generic handler, you can create a WCF service. You create a new WCF service by selecting the menu option Project, Add New Item and selecting the Ajax-enabled WCF Service project item. Name your WCF service InsertMovie.svc and click the Add button. Modify the WCF service so that it looks like Listing 3: Listing 3 – InsertMovie.svc using System.ServiceModel; using System.ServiceModel.Activation; namespace WebApplication1 { [ServiceBehavior(IncludeExceptionDetailInFaults=true)] [ServiceContract(Namespace = "")] [AspNetCompatibilityRequirements(RequirementsMode = AspNetCompatibilityRequirementsMode.Allowed)] public class MovieService { private MoviesDBEntities _dataContext = new MoviesDBEntities(); [OperationContract] public bool Insert(string title, string director) { // Create movie to insert var movieToInsert = new Movie { Title = title, Director = director }; // Save new movie to DB _dataContext.AddToMovies(movieToInsert); _dataContext.SaveChanges(); // Return movie (with primary key) return true; } } }   The WCF service in Listing 3 uses the Entity Framework to insert a record into the Movies database table. The service always returns the value true. Notice that the service in Listing 3 includes the following attribute: [ServiceBehavior(IncludeExceptionDetailInFaults=true)] You need to include this attribute if you want to get detailed error information back to the client. When you are building an application, you should always include this attribute. When you are ready to release your application, you should remove this attribute for security reasons. Using jQuery with the WCF Service Calling a WCF service from jQuery requires a little more work than calling a generic handler from jQuery. Here are some good blog posts on some of the issues with using jQuery with WCF: http://encosia.com/2008/06/05/3-mistakes-to-avoid-when-using-jquery-with-aspnet-ajax/ http://encosia.com/2008/03/27/using-jquery-to-consume-aspnet-json-web-services/ http://weblogs.asp.net/scottgu/archive/2007/04/04/json-hijacking-and-how-asp-net-ajax-1-0-mitigates-these-attacks.aspx http://www.west-wind.com/Weblog/posts/896411.aspx http://www.west-wind.com/weblog/posts/324917.aspx http://professionalaspnet.com/archive/tags/WCF/default.aspx The primary requirement when calling WCF from jQuery is that the request use JSON: The request must include a content-type:application/json header. Any parameters included with the request must be JSON encoded. Unfortunately, jQuery does not include a method for serializing JSON (Although, oddly, jQuery does include a parseJSON() method for deserializing JSON). Therefore, we need to use an additional library to handle the JSON serialization. The page in Listing 4 illustrates how you can call a WCF service from jQuery. Listing 4 – Default2.aspx <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title>Add Movie</title> <script src="http://ajax.microsoft.com/ajax/jquery/jquery-1.4.2.js" type="text/javascript"></script> <script src="Scripts/json2.js" type="text/javascript"></script> </head> <body> <form> <label>Title:</label> <input id="title" /> <br /> <label>Director:</label> <input id="director" /> </form> <button id="btnAdd">Add Movie</button> <script type="text/javascript"> $("#btnAdd").click(function () { // Convert the form into an object var data = { title: $("#title").val(), director: $("#director").val() }; // JSONify the data data = JSON.stringify(data); // Post it $.ajax({ type: "POST", contentType: "application/json; charset=utf-8", url: "MovieService.svc/Insert", data: data, dataType: "json", success: insertCallback }); }); function insertCallback(result) { // unwrap result result = result["d"]; if (result === true) { alert("Movie added!"); } else { alert("Could not add movie!"); } } </script> </body> </html> There are several things to notice about Listing 4. First, notice that the page includes both the jQuery library and Douglas Crockford’s JSON2 library: <script src="Scripts/json2.js" type="text/javascript"></script> You need to include the JSON2 library to serialize the form values into JSON. You can download the JSON2 library from the following location: http://www.json.org/js.html When you click the button to submit the form, the form data is converted into a JavaScript object: // Convert the form into an object var data = { title: $("#title").val(), director: $("#director").val() }; Next, the data is serialized into JSON using the JSON2 library: // JSONify the data var data = JSON.stringify(data); Finally, the form data is posted to the WCF service by calling the jQuery ajax() method: // Post it $.ajax({   type: "POST",   contentType: "application/json; charset=utf-8",   url: "MovieService.svc/Insert",   data: data,   dataType: "json",   success: insertCallback }); You can’t use the standard jQuery post() method because you must set the content-type of the request to be application/json. Otherwise, the WCF service will reject the request for security reasons. For details, see the Scott Guthrie blog post: http://weblogs.asp.net/scottgu/archive/2007/04/04/json-hijacking-and-how-asp-net-ajax-1-0-mitigates-these-attacks.aspx The insertCallback() method is called when the WCF service returns a response. This method looks like this: function insertCallback(result) {   // unwrap result   result = result["d"];   if (result === true) {       alert("Movie added!");   } else {     alert("Could not add movie!");   } } When we called the jQuery ajax() method, we set the dataType to JSON. That causes the jQuery ajax() method to deserialize the response from the WCF service from JSON into a JavaScript object automatically. The following value is passed to the insertCallback method: {"d":true} For security reasons, a WCF service always returns a response with a “d” wrapper. The following line of code removes the “d” wrapper: // unwrap result result = result["d"]; To learn more about the “d” wrapper, I recommend that you read the following blog posts: http://encosia.com/2009/02/10/a-breaking-change-between-versions-of-aspnet-ajax/ http://encosia.com/2009/06/29/never-worry-about-asp-net-ajaxs-d-again/ Summary In this blog entry, I explored two methods of inserting a database record using jQuery and .NET. First, we created a generic handler and called the handler from jQuery. This is a very low-level approach. However, it is a simple approach that works. Next, we looked at how you can call a WCF service using jQuery. This approach required a little more work because you need to serialize objects into JSON. We used the JSON2 library to perform the serialization. In the next blog post, I want to explore how you can use jQuery with OData and WCF Data Services.

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• SQL SERVER – Database Dynamic Caching by Automatic SQL Server Performance Acceleration

  - by pinaldave

  My second look at SafePeak’s new version (2.1) revealed to me few additional interesting features. For those of you who hadn’t read my previous reviews SafePeak and not familiar with it, here is a quick brief: SafePeak is in business of accelerating performance of SQL Server applications, as well as their scalability, without making code changes to the applications or to the databases. SafePeak performs database dynamic caching, by caching in memory result sets of queries and stored procedures while keeping all those cache correct and up to date. Cached queries are retrieved from the SafePeak RAM in microsecond speed and not send to the SQL Server. The application gets much faster results (100-500 micro seconds), the load on the SQL Server is reduced (less CPU and IO) and the application or the infrastructure gets better scalability. SafePeak solution is hosted either within your cloud servers, hosted servers or your enterprise servers, as part of the application architecture. Connection of the application is done via change of connection strings or adding reroute line in the c:\windows\system32\drivers\etc\hosts file on all application servers. For those who would like to learn more on SafePeak architecture and how it works, I suggest to read this vendor’s webpage: SafePeak Architecture. More interesting new features in SafePeak 2.1 In my previous review of SafePeak new I covered the first 4 things I noticed in the new SafePeak (check out my article “SQLAuthority News – SafePeak Releases a Major Update: SafePeak version 2.1 for SQL Server Performance Acceleration”): Cache setup and fine-tuning – a critical part for getting good caching results Database templates Choosing which database to cache Monitoring and analysis options by SafePeak Since then I had a chance to play with SafePeak some more and here is what I found. 5. Analysis of SQL Performance (present and history): In SafePeak v.2.1 the tools for understanding of performance became more comprehensive. Every 15 minutes SafePeak creates and updates various performance statistics. Each query (or a procedure execute) that arrives to SafePeak gets a SQL pattern, and after it is used again there are statistics for such pattern. An important part of this product is that it understands the dependencies of every pattern (list of tables, views, user defined functions and procs). From this understanding SafePeak creates important analysis information on performance of every object: response time from the database, response time from SafePeak cache, average response time, percent of traffic and break down of behavior. One of the interesting things this behavior column shows is how often the object is actually pdated. The break down analysis allows knowing the above information for: queries and procedures, tables, views, databases and even instances level. The data is show now on all arriving queries, both read queries (that can be cached), but also any types of updates like DMLs, DDLs, DCLs, and even session settings queries. The stats are being updated every 15 minutes and SafePeak dashboard allows going back in time and investigating what happened within any time frame. 6. Logon trigger, for making sure nothing corrupts SafePeak cache data If you have an application with many parts, many servers many possible locations that can actually update the database, or the SQL Server is accessible to many DBAs or software engineers, each can access some database directly and do some changes without going thru SafePeak – this can create a potential corruption of the data stored in SafePeak cache. To make sure SafePeak cache is correct it needs to get all updates to arrive to SafePeak, and if a DBA will access the database directly and do some changes, for example, then SafePeak will simply not know about it and will not clean SafePeak cache. In the new version, SafePeak brought a new feature called “Logon Trigger” to solve the above challenge. By special click of a button SafePeak can deploy a special server logon trigger (with a CLR object) on your SQL Server that actually monitors all connections and informs SafePeak on any connection that is coming not from SafePeak. In SafePeak dashboard there is an interface that allows to control which logins can be ignored based on login names and IPs, while the rest will invoke cache cleanup of SafePeak and actually locks SafePeak cache until this connection will not be closed. Important to note, that this does not interrupt any logins, only informs SafePeak on such connection. On the Dashboard screen in SafePeak you will be able to see those connections and then decide what to do with them. Configuration of this feature in SafePeak dashboard can be done here: Settings -> SQL instances management -> click on instance -> Logon Trigger tab. Other features: 7. User management ability to grant permissions to someone without changing its configuration and only use SafePeak as performance analysis tool. 8. Better reports for analysis of performance using 15 minute resolution charts. 9. Caching of client cursors 10. Support for IPv6 Summary SafePeak is a great SQL Server performance acceleration solution for users who want immediate results for sites with performance, scalability and peak spikes challenges. Especially if your apps are packaged or 3rd party, since no code changes are done. SafePeak can significantly increase response times, by reducing network roundtrip to the database, decreasing CPU resource usage, eliminating I/O and storage access. SafePeak team provides a free fully functional trial www.safepeak.com/download and actually provides a one-on-one assistance during such trial. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: About Me, Pinal Dave, PostADay, SQL, SQL Authority, SQL Performance, SQL Query, SQL Server, SQL Tips and Tricks, SQL Utility, T SQL, Technology

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• Survey: Which new database platforms are you adopting?

  Database technologies are always improving, which database platforms will you be using tomorrow? Red Gate wants to stay ahead to make sure you have the tools you need to do awesome work. Help us by completing this short survey. Compare and Sync database schemasWhether creating new databases or updating older ones, SQL Compare means no object gets left behind. It’s the gold standard, and you can try it free.

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• Database platform migration from Windows-32bit to Linux-64bit

  - by [email protected]

  We have a customer which have all they core business database on RAC over Windows OS. Last year they were affected by a virus that destroyed the registry and all their RAC environments were "OUT OF ORDER", the result, thousand people on vacation for a day.They were distrustful about Linux and after came an agreement to migrate their Enterprise Manager from Windows to Linux (OMS and Repository). How we did demonstrate how powerful and easy is RMAN to migrate databases across platforms.Fist of check of target platform is available from sourceSQL> select platform_name from v$db_transportable_platform;PLATFORM_NAME-----------------------------------------------------------Microsoft Windows IA (32-bit)Linux IA (32-bit)HP Tru64 UNIXLinux IA (64-bit)HP Open VMSMicrosoft Windows IA (64-bit)Linux 64-bit for AMDMicrosoft Windows 64-bit for AMDSolaris Operating System (x86)Check database object as directories that can change across platforms, also check external tables.Startup source database in read only modeRun the following RMAN ScriptRMAN> connect target / RMAN> convert database on target platform convert script 'c:/temp/convert_grid.rman'transport script 'c:/TEMP/transporta_grid.sql' new database 'gridbd' format 'c:/temp/gridmydb%U' db_file_name_convert 'C:\oracle\oradata\grid','/oracle/gridbd/data2/data';(Notice tha path change on db_file_name_convert)Move from source to target:PfileNew scriptsexternal table filesbfilesdata filesCheck pfile, and ensure that the paths are OKCreate temporary control file to connect rmanExecute the RMAN scriptRMAN> connect target / RMAN> @/home/oracle/pboixeda/win2lnx.rmanShutdown the instance and remove temporary control filesRecreate controlfile/s, take care about the used paths.Execute the transport script, transporta_grid.sqlDue we were moving from a 32-bit architecture to a 64-bit architecture, there is bug reported in 386990.1 note, we had to recreate OLAP , check the note for more details. Alter or Recreate all necessary objects Launch utlrpAfter this experience with Linux they are on the way to migrate all their RAC from 10gR2 on Windows to 11gR2 Linux 64 bit.Hope it helps

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• Force.com presents Database.com SQL Azure/Amazon RDS unfazed

  - by Sarang

  At the DreamForce 2010 event in San Francisco Force.com unveiled their next big thing in the Fat SaaS portfolio "Database.com".  I am still wondering how would they would've shelled out for that domain name. Now why would a already established SaaS player foray into a key building block like Database? Potentially allowing enterprises to build apps that do not utilize the Force.com stack! One key reason is being seen as the Fat SaaS player with evey trick in the SaaS space under his belt. You want CRM come hither, want a custom development PaaS like solution welcome home (VMForce), want all your apps to talk to a cloud DB and minimize latency by having it reside closer to you cloud apps? You've come to the right place sire! Other is potentially killing foray of smaller DB players like Oracle (Not surprisingly, the Database.com offering is a highly customized and scalable Oracle database) from entering the lucrative SaaS db marketplace. The feature set promised looks great out of the box for someone who likes to visualize cool new architectures. The ground realities are certainly going to be a lot different considering the SOAP/REST style access patterns in lieu of the comfortable old shoe of SQL. Microsoft suffered heavily with SDS (SQL Data Services) offering in early 2009 and had to pull the plug on the product only to reintroduce as a simple SQL Server in the cloud, SQL Windows Azure. Though MSFT is playing cool by providing OData semantics to work with SQL Windows Azure satisfying atleast some needs of the Web-Style to a DB. The other features like Social data models including Profiles, Status updates, feeds seem interesting as well. (Although I beleive social is just one of the aspects of large scale collaborative computing). All these features start "Free" for devs its a good news but the good news stops here. The overall pricing model of $ per Users per Transactions / Month is highly disproportionate compared to Amazon RDS (Based on MySQL) or SQL Windows Azure (Based on MSSQL). Roger Jennigs of Oakleaf did an interesting comparo based on 3, 10, 100, 500 users and it turns out that Database.com going by current understanding is way too expensive for the services on offer. The offering may not impact the decision for DotNet shops mulling their cloud stategy or even some Java/MySQL shops thinking about Amazon RDS, however for enterprises having already invested in other force.com offerings this could be a very important piece in the cloud strategy jigsaw. One which would address a key cloud DB issue of "Latency" for them at least it will help having the DB in the neighborhood. The tooling and "SQL like" access provider drivers (Think ODBC/JDBC) will be available later this year. Progress Software has already announced their JDBC driver stack for Database.com. It remains to be seen how effective the overall solutions proves to be in the longer run but for starts its a important decision towards consolidating Force.com's already strong positioning in the SaaS space. As always contrasting views are welcome! :)

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• The C++ Standard Template Library as a BDB Database (part 1)

  - by Gregory Burd

  If you've used C++ you undoubtedly have used the Standard Template Libraries. Designed for in-memory management of data and collections of data this is a core aspect of all C++ programs. Berkeley DB is a database library with a variety of APIs designed to ease development, one of those APIs extends and makes use of the STL for persistent, transactional data storage. dbstl is an STL standard compatible API for Berkeley DB. You can make use of Berkeley DB via this API as if you are using C++ STL classes, and still make full use of Berkeley DB features. Being an STL library backed by a database, there are some important and useful features that dbstl can provide, while the C++ STL library can't. The following are a few typical use cases to use the dbstl extensions to the C++ STL for data storage. When data exceeds available physical memory.Berkeley DB dbstl can vastly improve performance when managing a dataset which is larger than available memory. Performance suffers when the data can't reside in memory because the OS is forced to use virtual memory and swap pages of memory to disk. Switching to BDB's dbstl improves performance while allowing you to keep using STL containers. When you need concurrent access to C++ STL containers.Few existing C++ STL implementations support concurrent access (create/read/update/delete) within a container, at best you'll find support for accessing different containers of the same type concurrently. With the Berkeley DB dbstl implementation you can concurrently access your data from multiple threads or processes with confidence in the outcome. When your objects are your database.You want to have object persistence in your application, and store objects in a database, and use the objects across different runs of your application without having to translate them to/from SQL. The dbstl is capable of storing complicated objects, even those not located on a continous chunk of memory space, directly to disk without any unnecessary overhead. These are a few reasons why you should consider using Berkeley DB's C++ STL support for your embedded database application. In the next few blog posts I'll show you a few examples of this approach, it's easy to use and easy to learn.

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• Monitoring Database disk space

  - by Michael Freidgeim

  An article Data files: To Autogrow Or Not To Autogrow? recommends NOT to rely on auto-grow, because it causing delays in unplanned times.We should mtonitor database files(both data and log), and if they close to max capacity, manually increase the size. However it doesn't give references, how to monitor the free space inside databases. I've tried to look how to do it. It can be done manually using   execute sp_spaceused for the database in question or  sp_SOS (can be downloaded from http://searchsqlserver.techtarget.com/tip/Find-size-of-SQL-Server-tables-and-other-objects-with-stored-procedure)Alternatively you can run SQL commands as suggested in Http://www.sqlteam.com/forums/topic.asp?TOPIC_ID=82359 by Michael Valentine Jonesselect [FREE_SPACE_MB] = convert(decimal(12,2),round((a.size-fileproperty(a.name,'SpaceUsed'))/128.000,2)) from dbo.sysfiles aMore useful article Monitor database file sizes with SQL Server Jobs describes how to setup monitoring Finally I found the excellent articleManaging Database Data Usage With Custom Space Alerts, that can be followed even support personnel without much DBA experience.

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• 12/12 Live Webcast: Introducing Next-Generation Enterprise Auditing and Database Firewall

  - by jgelhaus

  Join Oracle Security gurus to hear how Oracle products monitor Oracle and non-Oracle database traffic, detect unauthorized activity including SQL injection attacks, and block internal and external threats from reaching the database. Hear how organizations such as TransUnion Interactive and SquareTwo Financial rely on Oracle to monitor and secure their Oracle and non-Oracle database environments. Register for the webcast here.

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• Announcing: Oracle Database 11g R2 Certification on Oracle Linux 6

  - by Monica Kumar

  Oracle Announces the Certification of the Oracle Database on Oracle Linux 6 and Red Hat Enterprise Linux 6 Yesterday we announced the certification of Oracle Database 11g R2 with Oracle Linux 6 and Unbreakable Enterprise Kernel. Here are the key highlights: Oracle Database 11g Release 2 (R2) and Oracle Fusion Middleware 11g Release 1 (R1) are immediately available on Oracle Linux 6 with the Unbreakable Enterprise Kernel. Oracle Database 11g R2 and Oracle Fusion Middleware 11g R1 will be available on Red Hat Enterprise Linux 6 (RHEL6) and Oracle Linux 6 with the Red Hat Compatible Kernel in 90 days. Oracle offers direct Linux support to customers running RHEL6, Oracle Linux 6, or a combination of both. Oracle Linux will continue to maintain compatibility with Red Hat Linux. Read the full press release. 

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• SQL SERVER – Core Concepts – Elasticity, Scalability and ACID Properties – Exploring NuoDB an Elastically Scalable Database System

  - by pinaldave

  I have been recently exploring Elasticity and Scalability attributes of databases. You can see that in my earlier blog posts about NuoDB where I wanted to look at Elasticity and Scalability concepts. The concepts are very interesting, and intriguing as well. I have discussed these concepts with my friend Joyti M and together we have come up with this interesting read. The goal of this article is to answer following simple questions What is Elasticity? What is Scalability? How ACID properties vary from NOSQL Concepts? What are the prevailing problems in the current database system architectures? Why is NuoDB  an innovative and welcome change in database paradigm? Elasticity This word’s original form is used in many different ways and honestly it does do a decent job in holding things together over the years as a person grows and contracts. Within the tech world, and specifically related to software systems (database, application servers), it has come to mean a few things - allow stretching of resources without reaching the breaking point (on demand). What are resources in this context? Resources are the usual suspects – RAM/CPU/IO/Bandwidth in the form of a container (a process or bunch of processes combined as modules). When it is about increasing resources the simplest idea which comes to mind is the addition of another container. Another container means adding a brand new physical node. When it is about adding a new node there are two questions which comes to mind. 1) Can we add another node to our software system? 2) If yes, does adding new node cause downtime for the system? Let us assume we have added new node, let us see what the new needs of the system are when a new node is added. Balancing incoming requests to multiple nodes Synchronization of a shared state across multiple nodes Identification of “downstate” and resolution action to bring it to “upstate” Well, adding a new node has its advantages as well. Here are few of the positive points Throughput can increase nearly horizontally across the node throughout the system Response times of application will increase as in-between layer interactions will be improved Now, Let us put the above concepts in the perspective of a Database. When we mention the term “running out of resources” or “application is bound to resources” the resources can be CPU, Memory or Bandwidth. The regular approach to “gain scalability” in the database is to look around for bottlenecks and increase the bottlenecked resource. When we have memory as a bottleneck we look at the data buffers, locks, query plans or indexes. After a point even this is not enough as there needs to be an efficient way of managing such large workload on a “single machine” across memory and CPU bound (right kind of scheduling)  workload. We next move on to either read/write separation of the workload or functionality-based sharing so that we still have control of the individual. But this requires lots of planning and change in client systems in terms of knowing where to go/update/read and for reporting applications to “aggregate the data” in an intelligent way. What we ideally need is an intelligent layer which allows us to do these things without us getting into managing, monitoring and distributing the workload. Scalability In the context of database/applications, scalability means three main things Ability to handle normal loads without pressure E.g. X users at the Y utilization of resources (CPU, Memory, Bandwidth) on the Z kind of hardware (4 processor, 32 GB machine with 15000 RPM SATA drives and 1 GHz Network switch) with T throughput Ability to scale up to expected peak load which is greater than normal load with acceptable response times Ability to provide acceptable response times across the system E.g. Response time in S milliseconds (or agreed upon unit of measure) – 90% of the time The Issue – Need of Scale In normal cases one can plan for the load testing to test out normal, peak, and stress scenarios to ensure specific hardware meets the needs. With help from Hardware and Software partners and best practices, bottlenecks can be identified and requisite resources added to the system. Unfortunately this vertical scale is expensive and difficult to achieve and most of the operational people need the ability to scale horizontally. This helps in getting better throughput as there are physical limits in terms of adding resources (Memory, CPU, Bandwidth and Storage) indefinitely. Today we have different options to achieve scalability: Read & Write Separation The idea here is to do actual writes to one store and configure slaves receiving the latest data with acceptable delays. Slaves can be used for balancing out reads. We can also explore functional separation or sharing as well. We can separate data operations by a specific identifier (e.g. region, year, month) and consolidate it for reporting purposes. For functional separation the major disadvantage is when schema changes or workload pattern changes. As the requirement grows one still needs to deal with scale need in manual ways by providing an abstraction in the middle tier code. Using NOSQL solutions The idea is to flatten out the structures in general to keep all values which are retrieved together at the same store and provide flexible schema. The issue with the stores is that they are compromising on mostly consistency (no ACID guarantees) and one has to use NON-SQL dialect to work with the store. The other major issue is about education with NOSQL solutions. Would one really want to make these compromises on the ability to connect and retrieve in simple SQL manner and learn other skill sets? Or for that matter give up on ACID guarantee and start dealing with consistency issues? Hybrid Deployment – Mac, Linux, Cloud, and Windows One of the challenges today that we see across On-premise vs Cloud infrastructure is a difference in abilities. Take for example SQL Azure – it is wonderful in its concepts of throttling (as it is shared deployment) of resources and ability to scale using federation. However, the same abilities are not available on premise. This is not a mistake, mind you – but a compromise of the sweet spot of workloads, customer requirements and operational SLAs which can be supported by the team. In today’s world it is imperative that databases are available across operating systems – which are a commodity and used by developers of all hues. An Ideal Database Ability List A system which allows a linear scale of the system (increase in throughput with reasonable response time) with the addition of resources A system which does not compromise on the ACID guarantees and require developers to learn new paradigms A system which does not force fit a new way interacting with database by learning Non-SQL dialect A system which does not force fit its mechanisms for providing availability across its various modules. Well NuoDB is the first database which has all of the above abilities and much more. In future articles I will cover my hands-on experience with it. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology Tagged: NuoDB

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• Using Live Data in Database Development Work

  - by Phil Factor

  Guest Editorial for Simple-Talk Newsletter... in which Phil Factor reacts with some exasperation when coming across a report that a majority of companies were still using financial and personal data for both developing and testing database applications. If you routinely test your development work using real production data that contains personal or financial information, you are probably being irresponsible, and at worst, risking a heavy financial penalty for your company. Surprisingly, over 80% of financial companies still do this. Plenty of data breaches and fraud have happened from the use of real data for testing, and a data breach is a nightmare for any organisation that suffers one. The cost of each data breach averages out at around $7.2 million in the US in notification, escalation, credit monitoring, fines, litigation, legal costs, and lost business due to customer churn, £1.9 million in the UK. 70% of data breaches are done from within the organisation. Real data can be exploited in a number of ways for malicious or criminal purposes. It isn't just the obvious use of items such as name and address, date of birth, social security number, and credit card and bank account numbers: Data can be exploited in many subtle ways, so there are excellent reasons to ensure that a high priority is given to the detection and prevention of any data breaches. You'll never successfully guess all the ways that real data can be exploited maliciously, or the ease with which it can be accessed. It would be silly to argue that developers never need access to a copy of the database containing live data. Developers sometimes need to track a bug that can only be replicated on the data from the live database. However, it has to be done in a very restrictive harness. The law makes no distinction between development and production databases when a data breach occurs, so the data has to be held with all appropriate security measures in place. In Europe, the use of personal data for testing requires the explicit consent of the people whose data is being held. There are federal standards such as GLBA, PCI DSS and HIPAA, and most US States have privacy legislation. The task of ensuring compliance and tight security in such circumstances is an expensive and time-consuming overhead. The developer is likely to suffer investigation if a data breach occurs, even if the company manages to stay in business. Ironically, the use of copies of live data isn't usually the most effective way to develop or test your data. Data is usually time-specific and isn't usually current by the time it is used for testing, Existing data doesn't help much for new functionality, and every time the data is refreshed from production, any test data is likely to be overwritten. Also, it is not always going to test all the 'edge' conditions that are likely to flush out bugs. You still have the task of simulating the dynamics of actual usage of the database, and here you have no alternative to creating 'spoofed' data. Because of the complexities of relational data, It used to be that there was no realistic alternative to developing and testing with live data. However, this is no longer the case. Real data can be obfuscated, or it can be created entirely from scratch. The latter process used to be impractical, now that there are plenty of third-party tools to choose from. The process of obfuscation isn't risk free. The process must access the live data, and the success of the obfuscation process has to be carefully monitored. Database data security isn't an exciting topic to you or I, but to a hacker it can be an all-consuming obsession, especially if there is financial or political gain involved. This is not the sort of adversary one would wish for and it is far better to accept, and work with, security restrictions that exist for using live data in database development work, especially when the tools exist to create large realistic database test data that can be better for several aspects of testing.

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• Announcement: Oracle Database Appliance 2.4 patch update now available

  - by uwes

  The Oracle Database Appliance 2.4 patch is now available from My Oracle Support (MOS).  If you search for the Oracle Database Appliance 2.4.0.0.0 Kit under Patches it will display the newly uploaded bundles. The patch highlights include: Normal redundancy (double-mirroring) option providing 6TB of usable storage Enhanced Diagnostics - Trace File Analyzer and ODACHK Also, if you review the README, you may see content that says:        "The grid infrastructure and database patching, both are rolling upgradable. During our patching, we patch the node 1 first and when completed, we patch the node 2." I would like to clarify that the 'infrastructure' updates (OS, Firmware, ILOM, etc) will require a  short downtime of the ODA while it is applied.  When you update the grid infrastructure (--gi), the appliance manager verifies that the infrastructure was updated so you cannot just patch the GI without first updating the infrastructure. The high level update patch steps include (but not limited to): Download patch update to your ODA The --infra (infrastructure) is updated and ODA Databases are down and the ODA is/may be rebooted ODA and GI/Databases are restarted Issue the command to update the Grid Infrastructure/databases (The order of the steps are completed automatically and you cannot control when the nodes are brought up and down during the patching) Node 1 -- shutdown databases and GI Node 1 -- patch GI/database Node 1 -- bring up databases and GI Node 2 -- shutdown databases and GI Node 2 -- patch GI/database Node 2 -- bring up databases and GI A replay from Friday's with Sohan on the 2.4 release can be found here.  The PDF of the presentation is here. The Data Sheet, WP, and 2.4 Configurator are available on the ODA OTN site.

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• Oracle Database 11g Release 2: Optimized for SAP

  - by jenny.gelhausen

  With the release of Oracle Database 11g Release 2 Enterprise Edition, Oracle has further enhanced its long-standing commitment to joint Oracle and SAP AG customers. Get more details on the release. The Oracle Database Insider sat down with Gerhard Kuppler, senior director Corporate SAP Account at Oracle, to find out just how much Oracle Database 11g Release 2 can impact SAP customers. Check out the interview details.

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• The Database as Intellectual Property

  - by Jonathan Kehayias

  Every so often, a question shows up on the forums in the form of, “How do I prevent anyone from accessing my database schema, including local administrators and sysadmins in SQL Server?”  I usually laugh a little shake my head when I read a question like this because it demonstrates an complete lack of understanding of the power an administrator has over SQL Server.  The simple answer is this: If you don’t want your database schema to ever be accessed or known, don’t distribute your database....(read more)

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• Add a database to use with locate command

  - by Pedro Teran

  i would like to know if anyone knows how I can create a database of a file system on my computer. so I can choose this data base to search for files on this file system efficiently. I ask this question since in man locate I found that I can choose a database for a different file system. Also would be grate if /var/lib/mlocate/mlocate.db database can have the data of 2 disks any approach ideas or others would be greatly appreciated

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• Unable to add users to Microsoft Dynamics CRM 4.0 after database restore

  - by Wes Weeks

  Working with a client in our Multi-tenant CRM environment who was doing a database migration into CRM and as part of the process, a backup of their Organization_MSCRM database was taken just prior to starting the migration in case it needed to be restored and run a second time. In this case it did, so I restored the database and let the client know he should be good to go.  A few hours later I received a call that they were unable to add some new users, they would appear as available when using the add multiple user wizard, but anyone added would not be added to CRM.  It was also disucussed that these users had been added to CRM initally AFTER the database backup had been taken. I turned on tracing and tried to add the users through both the single user form and multiple user interface and was unable to do so.  The error message in the logs wasn't much help: Unexpected error adding user [email protected]: Microsoft.Crm.CrmException: INVALID_WRPC_TOKEN: Validate WRPC Token: WRPCTokenState=Invalid, TOKEN_EXPIRY=4320, IGNORE_TOKEN=False Searching on Google or bing didn't offer any assitance.  Apparently not a very common problem, or no one has been able to resolve. I did some searching in the MSCRM_CONFIG database and found that their are several user tables there and after getting my head around the structure found that there were enties here for users that were not part of the restored DB.  It seems that new users are added to both the Orgnaization_MSCRM and MSCRM_CONFIG and after the restore these were out of sync. I needed to remove the extra entries in order to address.  Restoring the MSCRM_CONFIG database was not an option as other clients could have been adding users at this point and to restore would risk breaking their instances of CRM.  Long story short, I was finally able to generate a script to remove the bad entries and when I tried to add users again, I was succesful.  In case someone else out there finds themselves in a similar situation, here is the script I used to delete the bad entries. DECLARE @UsersToDelete TABLE (   UserId uniqueidentifier )   Insert Into @UsersToDelete(UserId) Select UserId from [MSCRM_CONFIG].[dbo].[SystemUserOrganizations] Where CrmuserId Not in (select systemuserid from Organization_MSCRM.dbo.SystemUserBase) And OrganizationId = '00000000-643F-E011-0000-0050568572A1' --Id From the Organization table for this instance   Delete From [MSCRM_CONFIG].[dbo].[SystemUserAuthentication]   Where UserId in (Select UserId From @UsersToDelete)   Delete From [MSCRM_CONFIG].[dbo].[SystemUserOrganizations] Where UserId in (Select UserId From @UsersToDelete)   Delete From [MSCRM_CONFIG].[dbo].[SystemUser] Where Id in (Select UserId From @UsersToDelete)

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• Oracle Database As Seen at Sapphire 2010

  - by jenny.gelhausen

  Seen around the Orange County Convention Center in Orlando Florida at the May 16-19th SAPPHIRE 2010 conference Oracle Database is the #1 Database for SAP applications Oracle Database 11g Release 2 is available for SAP. By upgrading you can lower the cost of your SAP applications infrastructure and improve your quality of service, so we encourage you to consider the upgrade.

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• Oracle Database 11g Release 2 for Windows available!

  - by Mike Dietrich

  Hi there, just returned from vacation - and the Easter bunny (was its name Tux??) just delivered the Windows release (32bit and 64bit) of Oracle Database 11g Release 2. It's available for download from edelivery.oracle.com or OTN: Oracle Database 11g Release 2 for Windows 32-bit Oracle Database 11g Release 2 for Windows 64-bit And if you wonder yourself why it took sooooooo long to release Oracle Database 11g Release 2 on the Windows platform: The developers have incorporated a lot of the available fixes on top of 11.2.0.1.0 - so it's more a 11.2.0.1.1/2 ;-) And don't forget to download the newest version of rhe upgrade slides: http://apex.oracle.com/folien Use the keyword (Schluesselwort): upgrade112

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