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  • Creating ASP.NET Admin Pages

    In the tutorial series for ASP.NET 3.5 Master Page Design using Query String I explained in detail how to create an ASP.NET website using master pages and query string techniques. This tutorial series will show you how to create admin pages for your ASP.NET MasterPage Query String driven website.... Self-Service Ad Manager Sell Ads directly to advertisers - Keep 100% of your ad revenue - Free access

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  • What are the benefits of Android way of "saving memory" - explicitly passing Context objects everywhere?

    - by Sarge Borsch
    Turned out, this question is not easy to formulate for me, but let's try. In Android, pretty much any UI object depends on a Context, and has defined lifetime. It also can destroy and recreate UI objects and even whole application process at any time, and so on. This makes coding asynchronous operations correctly not straightforward. (and sometimes very cumbersome) But I never have seen a real explanation, why it's done that way? There are other OSes, including mobile OSes (iOS, for example), that don't do such things. So, what are the wins of Android way (Activities & Contexts)? Does that allow Android applications to use much less RAM, or maybe there are other benefits?

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  • Asynchronous vs Synchronous vs Threading in an iPhone App

    - by Coocoo4Cocoa
    I'm in the design stage for an app which will utilize a REST web service and sort of have a dilemma in as far as using asynchronous vs synchronous vs threading. Here's the scenario. Say you have three options to drill down into, each one having its own REST-based resource. I can either lazily load each one with a synchronous request, but that'll block the UI and prevent the user from hitting a back navigation button while data is retrieved. This case applies almost anywhere except for when your application requires a login screen. I can't see any reason to use synchronous HTTP requests vs asynchronous because of that reason alone. The only time it makes sense is to have a worker thread make your synchronous request, and notify the main thread when the request is done. This will prevent the block. The question then is bench marking your code and seeing which has more overhead, a threaded synchronous request or an asynchronous request. The problem with asynchronous requests is you need to either setup a smart notification or delegate system as you can have multiple requests for multiple resources happening at any given time. The other problem with them is if I have a class, say a singleton which is handling all of my data, I can't use asynchronous requests in a getter method. Meaning the following won't go: - (NSArray *)users { if(users == nil) users = do_async_request // NO GOOD return users; } whereas the following: - (NSArray *)users { if(users == nil) users == do_sync_request // OK. return users; } You also might have priority. What I mean by priority is if you look at Apple's Mail application on the iPhone, you'll notice they first suck down your entire POP/IMAP tree before making a second request to retrieve the first 2 lines (the default) of your message. I suppose my question to you experts is this. When are you using asynchronous, synchronous, threads -- and when are you using either async/sync in a thread? What kind of delegation system do you have setup to know what to do when a async request completes? Are you prioritizing your async requests? There's a gamut of solutions to this all too common problem. It's simple to hack something out. The problem is, I don't want to hack and I want to have something that's simple and easy to maintain.

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  • ASP.NET MVC 2 Cancel Asynchronous Action

    - by Sean Carpenter
    The MSDN documentation for using an asynchronous controller mentions choosing an asynchronous controller when you want to provide a way for users to cancel requests. I couldn't find any documentation related to actually allowing users to cancel asynchronous requests, however. Is there a way to indicate to ASP.Net and/or the MVC framework that a request should be canceled?

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  • Does ASP.Net MVC require you to use master pages?

    - by stocherilac
    My group is working on a new web application and is considering using MVC. However, there are members who would rather include pages than use master pages. Is this possible to do in ASP.NET MVC? In the small amount of time that I've poked around with MVC I have not yet been able to figure out how one might accomplish that.

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  • Informing Googlebot for deprecated pages

    - by trante
    I publish timetables in my website. For example last year I published Number 2 bus Summer 2013 timetable. I has pretty good ranking on Google SERPs for number 2 bus timetable But this year I added a new page with the name "Number 2 bus Summer 2014 timetable". When users search number 2 bus timetable in Google, they find 2013 timetable in first page of SERPs. But I want them to find 2014 timetable. Thy can reach 2014 page with the keywords number 2 bus timetable 2014. But most of the users doesn't write year name. So what's the proper way to say Googlebot that 2013 page is deprecated and newer version is 2014 page ? I created a link from 2013 page to 2013 page and added a deprecation alert for visitors. But I still see 2013 timetable in first page of Google SERPs. Of course it is possible to 301 redirect, 2013 page to 2014 page. But I want users to reach old pages to compare the differences between years. (As you would guess I have many pages like this.) Edit: Why I don't put timetables on same page and show different years' timetables with sorting. Because my old pages has good pagerank scores or SERPs. Removing these old page will remove them.

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  • Moodle 2 pages loading up to 2000% faster

    - by TJ
    On average our Moodle 2 pages were loading in 2.8 seconds, now they load in as little as 0.12 seconds, so that’s like 2333.333% faster!What was it I hear you say?Well it was the database connection, or more correctly the database library. I was using FreeTDS http://docs.moodle.org/22/en/Installing_MSSQL_for_PHP, but now I’m using the new Microsoft Drivers 3.0 for PHP for SQL Server http://www.microsoft.com/en-us/download/details.aspx?id=20098. I’m in a Windows Server IT department, and in both our live and development environments, we have Moodle 2.2.3, IIS 7.5, and PHP 5.3.10 running on two Windows Server 2008 R2 servers and using MS Network Load Balancing.Since moving to Moodle 2, the pages have always loaded much more slowly than they did in Moodle 1.9, I’ve been chasing this issue for quite a while. I had previously tried the Microsoft Drivers for PHP for SQL Server 2.0, but my testing showed it was slower than the FreeTDS driver.Then yesterday I found Microsoft had released the new version, Microsoft Drivers 3.0 for PHP for SQL Server, so I thought I’d give it a run, and wow what a difference it made.Pages that were loading in 2.8 seconds, now they load in as little as 0.12 seconds, 2333.333% faster…I have more testing to do, but so far it’s looking good, I have scheduled multi user load testing for early next week (fingers crossed).To make the change all I need to do was,download the driverscopy the relevant files to PHP\ext (for us they were php_pdo_sqlsrv_53_nts.dll and php_sqlsrv_53_nts.dll) install the Microsoft SQL Server 2012 Native Client x64 http://www.microsoft.com/en-us/download/details.aspx?id=29065 add to PHP.ini, extension=php_pdo_sqlsrv_53_nts.dll, extension=php_sqlsrv_53_nts.dllremove form PHP.ini, extension=php_dblib.dllvchange in PHP.ini, mssql.textlimit = 20971520 and mssql.textsize = 20971520change Moodle config.php, $CFG->dbtype = 'sqlsrv'; and 'dbpersist' => Trueand then reboot and test…I've browsed courses, backed up/restored some really large and complicated courses, deleted courses etc. etc. all good.Still more testing to do but, hey this is good start...Hope this helps anyone experiencing the same slowness…

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  • How to Change System Application Pages (Like AccessDenied.aspx, Signout.aspx etc)

    - by Jayant Sharma
    An advantage of SharePoint 2010 over SharePoint 2007 is, we can programatically change the URL of System Application Pages. For Example, It was not very easy to change the URL of AccessDenied.aspx page in SharePoint 2007 but in SharePoint 2010 we can easily change the URL with just few lines of code. For this purpose we have two methods available: GetMappedPage UpdateMappedPage: returns true if the custom application page is successfully mapped; otherwise, false. You can override following pages. Member name Description None AccessDenied Specifies AccessDenied.aspx. Confirmation Specifies Confirmation.aspx. Error Specifies Error.aspx. Login Specifies Login.aspx. RequestAccess Specifies ReqAcc.aspx. Signout Specifies SignOut.aspx. WebDeleted Specifies WebDeleted.aspx. ( http://msdn.microsoft.com/en-us/library/microsoft.sharepoint.administration.spwebapplication.spcustompage.aspx ) So now Its time to implementation, using (SPSite site = new SPSite(http://testserver01)) {   //Get a reference to the web application.   SPWebApplication webApp = site.WebApplication;   webApp.UpdateMappedPage(SPWebApplication.SPCustomPage.AccessDenied, "/_layouts/customPages/CustomAccessDenied.aspx");   webApp.Update(); } Similarly, you can use  SPCustomPage.Confirmation, SPCustomPage.Error, SPCustomPage.Login, SPCustomPage.RequestAccess, SPCustomPage.Signout and SPCustomPage.WebDeleted to override these pages. To  reset the mapping, set the Target value to Null like webApp.UpdateMappedPage(SPWebApplication.SPCustomPage.AccessDenied, null);webApp.Update();One restricted to location in the /_layouts folder. When updating the mapped page, the URL has to start with “/_layouts/”. Ref: http://msdn.microsoft.com/en-us/library/gg512103.aspx#bk_spcustapp http://msdn.microsoft.com/en-us/library/microsoft.sharepoint.administration.spwebapplication.updatemappedpage.aspx

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  • How to handle multiple pages of the same site with the same outlinks

    - by pandafromchina
    I am developing a back link tool for Chinese SEO (our web site URL is: http://link.aizhan.com just like ahrefs.com. I encountered a problem which is how to handle multiple pages of the same site with the same out links. For example: Most pages of bbs.chinaz.com have the same out links such as: bbs.chinaz.com/Tea/thread-6293993-1-1.html bbs.chinaz.com/Tea/list-1.html bbs.chinaz.com/alimama/thread-6265032-1-1.html bbs.chinaz.com/alimama/thread-6265032-2-1.html?userid=-1&extParms= bbs.chinaz.com/Shuiba/list-1.html bbs.chinaz.com/FeedBack/thread-4456753-1-1.html etc.. All of the pages have the same out links in the top of the page: www.cnzz.com(anchor text:????) www.313.com(????) www.idc123.com(????) Suppose I store these outlinks into database. The SEO will find there are six backlinks from bbs.chinaz.com of www.cnzz.com. This is obviously no sense for the SEO. Can you tell me how do you deal with this problem?

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  • SQL SERVER – Data Pages in Buffer Pool – Data Stored in Memory Cache

    - by pinaldave
    This will drop all the clean buffers so we will be able to start again from there. Now, run the following script and check the execution plan of the query. Have you ever wondered what types of data are there in your cache? During SQL Server Trainings, I am usually asked if there is any way one can know how much data in a table is stored in the memory cache? The more detailed question I usually get is if there are multiple indexes on table (and used in a query), were the data of the single table stored multiple times in the memory cache or only for a single time? Here is a query you can run to figure out what kind of data is stored in the cache. USE AdventureWorks GO SELECT COUNT(*) AS cached_pages_count, name AS BaseTableName, IndexName, IndexTypeDesc FROM sys.dm_os_buffer_descriptors AS bd INNER JOIN ( SELECT s_obj.name, s_obj.index_id, s_obj.allocation_unit_id, s_obj.OBJECT_ID, i.name IndexName, i.type_desc IndexTypeDesc FROM ( SELECT OBJECT_NAME(OBJECT_ID) AS name, index_id ,allocation_unit_id, OBJECT_ID FROM sys.allocation_units AS au INNER JOIN sys.partitions AS p ON au.container_id = p.hobt_id AND (au.type = 1 OR au.type = 3) UNION ALL SELECT OBJECT_NAME(OBJECT_ID) AS name, index_id, allocation_unit_id, OBJECT_ID FROM sys.allocation_units AS au INNER JOIN sys.partitions AS p ON au.container_id = p.partition_id AND au.type = 2 ) AS s_obj LEFT JOIN sys.indexes i ON i.index_id = s_obj.index_id AND i.OBJECT_ID = s_obj.OBJECT_ID ) AS obj ON bd.allocation_unit_id = obj.allocation_unit_id WHERE database_id = DB_ID() GROUP BY name, index_id, IndexName, IndexTypeDesc ORDER BY cached_pages_count DESC; GO Now let us run the query above and observe the output of the same. We can see in the above query that there are four columns. Cached_Pages_Count lists the pages cached in the memory. BaseTableName lists the original base table from which data pages are cached. IndexName lists the name of the index from which pages are cached. IndexTypeDesc lists the type of index. Now, let us do one more experience here. Please note that you should not run this test on a production server as it can extremely reduce the performance of the database. DBCC DROPCLEANBUFFERS This will drop all the clean buffers and we will be able to start again from there. Now run following script and check the execution plan for the same. USE AdventureWorks GO SELECT UnitPrice, ModifiedDate FROM Sales.SalesOrderDetail WHERE SalesOrderDetailID BETWEEN 1 AND 100 GO The execution plans contain the usage of two different indexes. Now, let us run the script that checks the pages cached in SQL Server. It will give us the following output. It is clear from the Resultset that when more than one index is used, datapages related to both or all of the indexes are stored in Memory Cache separately. Let me know what you think of this article. I had a great pleasure while writing this article because I was able to write on this subject, which I like the most. In the next article, we will exactly see what data are cached and those that are not cached, using a few undocumented commands. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: DMV, Pinal Dave, SQL, SQL Authority, SQL Optimization, SQL Query, SQL Scripts, SQL Server, SQL Tips and Tricks, T SQL, Technology Tagged: SQL DMV

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  • How do you use asynchronous ORMs without huge callback chains?

    - by hornairs
    I'm using the relatively immature Joose Javascript ORM plugin (project page) to persist objects in an Appcelerator Titanium (company page) mobile project. Since it's client side storage, the application has to check to see if the database is initialized before starting up the ORM since it inspects the DB tables to construct the classes. My problem is that this sequence of operations (and if this one is like this, other things down the road) takes a lot of callbacks to complete. I have a lot of jumping around in the code that isn't apparent to a maintainer and results in some complex call graphs and whatnot. So, I ask these questions: How would you asynchronously initialize a database and populate it with seed data using an ORM that needs the schema to be correct to function? Do you have any general strategies or links for async/event driven programming and keeping the call graph simple and understandable? Do you have any suggestions for Javascript ORMs/meta object systems that work with HTML 5 as a storage engine and are hopefully framework agnostic? Am I just a big newb and should be able to work this out with ease? Thanks folks!

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  • Can Tornado communicate with Cassandra, in Non-blocking asynchronous style?

    - by takaomag
    I'm working on a web project, which have to process so many client requests. So I am considering to use Cassandra and tornado. Tornado seems to have a build-in client(tornado.httpclient.AsyncHTTPClient), which can do http Non-Blocking request. But, Cassandra uses Thrift protocol. Using Thrift, Tornado seems to be blocked while quering to Cassandra. Has anyone got expereince? Please suggest how should I do. Or, is there any add-on module for this purpose? Thanks.

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  • Socket : can an asynchronous Receive returns without reading all the bytes I asked for?

    - by NorthWind
    Hi; I was reading an article on Vadym Stetsiak's blog about how to transfer variable length messages with async sockets (url: http://vadmyst.blogspot.com/2008/03/part-2-how-to-transfer-fixed-sized-data.html). He says : What to expect when multiple messages arrive at the server? While dealing with multiple messages one has to remember that receive operation can return arbitrary number of bytes being read from the net. Typically that size is from 0 to specified buffer length in the Receive or BeginReceive methods. So, even if I tell BeginReceive to read 100 bytes, it may read less than that and returns??? I am developing a network-enabled software (TCP/IP), and I always receive the same exact number of bytes I asked for. I don't even understand the logic : why would Receive completes asynchronously if it didn't get every byte I asked for ... just keep waiting. Maybe it has something to do with IP vs TCP? Thank you for your help.

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  • Create a new delegate class for each asynchronous image download?

    - by Charles S.
    First, I'm using an NSURLConnection to download JSON data from twitter. Then, I'm using a second NSURLConnection to download corresponding user avatar images (the urls to the images are parsed from the first data download). For the first data connection, I have my TwitterViewController set as the NSURLConnection delegate. I've created a separate class (ImageDownloadDelegate) to function as the delegate for a second NSURLConnection that handles the images. After the tweets are finished downloading, I'm using this code to get the avatars: for(int j=0; j<[self.tweets count]; j++){ ImageDownloadDelegate *imgDelegate = [[ImageDownloadDelegate alloc] init]; Tweet *myTweet = [self.tweets objectAtIndex:j]; imgDelegate.tweet = myTweet; imgDelegate.table = timeline; NSURLRequest* request = [NSURLRequest requestWithURL:[NSURL URLWithString:myTweet.imageURL] cachePolicy:NSURLRequestUseProtocolCachePolicy timeoutInterval:60]; imgConnection = [[NSURLConnection alloc] initWithRequest:request delegate:imgDelegate]; [imgDelegate release]; } So basically a new instance of the delegate class is created for each image that needs to be downloaded. Is this the best way to go about this? But then there's no way to figure out which image is associate with which tweet, correct? The algorithm works fine... I'm just wondering if I'm going about it the most efficient way.

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  • JavaScript: How can I delay running some JS code until ALL of my asynchronous JS files downloaded?

    - by Henryh
    UPDATE: I have the following code: <script type="text/javascript"> function addScript(url) { var script = document.createElement('script'); script.src = url; document.getElementsByTagName('head')[0].appendChild(script); } addScript('http://example.com/One.js'); addScript('http://example.com/Two.js'); addScript('http://example.com/Three.js'); addScript('http://example.com/Four.js'); ... // run code below this point once both Two.js & Three.js has been downloaded and excuted </script> How can I prevent code from executing until all required JS have been downloaded and executed? In my example above, those required files being Two.js and Three.js.

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  • Postgres : Post statement (or insert) asynchronous, non-blocking processing.

    - by Hassan Syed
    I'm wondering if it is possible, that after a collection of rows is inserted, to initiate an operation that is executed asynchronously, is non-blocking, and doesn't need to inform the originator of the request - of the result. I am working with large amounts of events and I can guarantee that the post-insert logic will not fail -- I just want to have a single insert thread in my event-sources, and I want this thread to keep flying without blocking, and without being responsible for any post-delivery book-keeping. I can tell you that I would potentially have a 100 of these jobs executing concurrently and each job might operate on 5 tables with anywhere between 200-1000 inserts on each of these tables. A hint in the right direction should be enough.

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  • What's the best way to cancel an asynchronous WCF request?

    - by Pwninstein
    (Assuming a WCF method called "MyFunction") Currently, to support canceling a WCF request, I'm using the BeginMyFunction/EndMyFunction methods generated by svcutil (and handling an isCanceled flag when dispatching the results to the main thread). I'd like to use the MyFunctionAsync method (and hooking into MyFunctionAsyncCompleted event instead) for async calls instead of Begin/End. What is the best/supported way to handle canceling WCF requests if using MyFunctionAsyncCompleted, and still ensuring that the event doesn't get fired on a page that's no longer loaded (i.e. page navigation within a frame). Thanks!

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  • What happens if an asynchronous delegate call never returns?

    - by RichardHowells
    I found a decent looking example of how to call a delegate asynchronously with a timeout... http://www.eggheadcafe.com/tutorials/aspnet/847c94bf-4b8d-4a66-9ae5-5b61f049019f/basics-make-any-method-c.aspx. In summary it uses WaitOne with a timeout to determine if the call does not return before the timeout expires. I also know that you should have an EndInvoke to match each BeginInvoke. So what happens if the wait timeout expires? We (presumably) DON'T want to call EndInvoke as that will block. The code can go on to do 'other things', but have we leaked anything? Is there some poor thread someplace blocked waiting for a return that's never going to happen? Have we leaked some memory where the result-that-will-never-return was going to be placed?

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  • SQL Server &ndash; Undelete a Table and Restore a Single Table from Backup

    - by Mladen Prajdic
    This post is part of the monthly community event called T-SQL Tuesday started by Adam Machanic (blog|twitter) and hosted by someone else each month. This month the host is Sankar Reddy (blog|twitter) and the topic is Misconceptions in SQL Server. You can follow posts for this theme on Twitter by looking at #TSQL2sDay hashtag. Let me start by saying: This code is a crazy hack that is to never be used unless you really, really have to. Really! And I don’t think there’s a time when you would really have to use it for real. Because it’s a hack there are number of things that can go wrong so play with it knowing that. I’ve managed to totally corrupt one database. :) Oh… and for those saying: yeah yeah.. you have a single table in a file group and you’re restoring that, I say “nay nay” to you. As we all know SQL Server can’t do single table restores from backup. This is kind of a obvious thing due to different relational integrity (RI) concerns. Since we have to maintain that we have to restore all tables represented in a RI graph. For this exercise i say BAH! to those concerns. Note that this method “works” only for simple tables that don’t have LOB and off rows data. The code can be expanded to include those but I’ve tried to leave things “simple”. Note that for this to work our table needs to be relatively static data-wise. This doesn’t work for OLTP table. Products are a perfect example of static data. They don’t change much between backups, pretty much everything depends on them and their table is one of those tables that are relatively easy to accidentally delete everything from. This only works if the database is in Full or Bulk-Logged recovery mode for tables where the contents have been deleted or truncated but NOT when a table was dropped. Everything we’ll talk about has to be done before the data pages are reused for other purposes. After deletion or truncation the pages are marked as reusable so you have to act fast. The best thing probably is to put the database into single user mode ASAP while you’re performing this procedure and return it to multi user after you’re done. How do we do it? We will be using an undocumented but known DBCC commands: DBCC PAGE, an undocumented function sys.fn_dblog and a little known DATABASE RESTORE PAGE option. All tests will be on a copy of Production.Product table in AdventureWorks database called Production.Product1 because the original table has FK constraints that prevent us from truncating it for testing. -- create a duplicate table. This doesn't preserve indexes!SELECT *INTO AdventureWorks.Production.Product1FROM AdventureWorks.Production.Product   After we run this code take a full back to perform further testing.   First let’s see what the difference between DELETE and TRUNCATE is when it comes to logging. With DELETE every row deletion is logged in the transaction log. With TRUNCATE only whole data page deallocations are logged in the transaction log. Getting deleted data pages is simple. All we have to look for is row delete entry in the sys.fn_dblog output. But getting data pages that were truncated from the transaction log presents a bit of an interesting problem. I will not go into depths of IAM(Index Allocation Map) and PFS (Page Free Space) pages but suffice to say that every IAM page has intervals that tell us which data pages are allocated for a table and which aren’t. If we deep dive into the sys.fn_dblog output we can see that once you truncate a table all the pages in all the intervals are deallocated and this is shown in the PFS page transaction log entry as deallocation of pages. For every 8 pages in the same extent there is one PFS page row in the transaction log. This row holds information about all 8 pages in CSV format which means we can get to this data with some parsing. A great help for parsing this stuff is Peter Debetta’s handy function dbo.HexStrToVarBin that converts hexadecimal string into a varbinary value that can be easily converted to integer tus giving us a readable page number. The shortened (columns removed) sys.fn_dblog output for a PFS page with CSV data for 1 extent (8 data pages) looks like this: -- [Page ID] is displayed in hex format. -- To convert it to readable int we'll use dbo.HexStrToVarBin function found at -- http://sqlblog.com/blogs/peter_debetta/archive/2007/03/09/t-sql-convert-hex-string-to-varbinary.aspx -- This function must be installed in the master databaseSELECT Context, AllocUnitName, [Page ID], DescriptionFROM sys.fn_dblog(NULL, NULL)WHERE [Current LSN] = '00000031:00000a46:007d' The pages at the end marked with 0x00—> are pages that are allocated in the extent but are not part of a table. We can inspect the raw content of each data page with a DBCC PAGE command: -- we need this trace flag to redirect output to the query window.DBCC TRACEON (3604); -- WITH TABLERESULTS gives us data in table format instead of message format-- we use format option 3 because it's the easiest to read and manipulate further onDBCC PAGE (AdventureWorks, 1, 613, 3) WITH TABLERESULTS   Since the DBACC PAGE output can be quite extensive I won’t put it here. You can see an example of it in the link at the beginning of this section. Getting deleted data back When we run a delete statement every row to be deleted is marked as a ghost record. A background process periodically cleans up those rows. A huge misconception is that the data is actually removed. It’s not. Only the pointers to the rows are removed while the data itself is still on the data page. We just can’t access it with normal means. To get those pointers back we need to restore every deleted page using the RESTORE PAGE option mentioned above. This restore must be done from a full backup, followed by any differential and log backups that you may have. This is necessary to bring the pages up to the same point in time as the rest of the data.  However the restore doesn’t magically connect the restored page back to the original table. It simply replaces the current page with the one from the backup. After the restore we use the DBCC PAGE to read data directly from all data pages and insert that data into a temporary table. To finish the RESTORE PAGE  procedure we finally have to take a tail log backup (simple backup of the transaction log) and restore it back. We can now insert data from the temporary table to our original table by hand. Getting truncated data back When we run a truncate the truncated data pages aren’t touched at all. Even the pointers to rows stay unchanged. Because of this getting data back from truncated table is simple. we just have to find out which pages belonged to our table and use DBCC PAGE to read data off of them. No restore is necessary. Turns out that the problems we had with finding the data pages is alleviated by not having to do a RESTORE PAGE procedure. Stop stalling… show me The Code! This is the code for getting back deleted and truncated data back. It’s commented in all the right places so don’t be afraid to take a closer look. Make sure you have a full backup before trying this out. Also I suggest that the last step of backing and restoring the tail log is performed by hand. USE masterGOIF OBJECT_ID('dbo.HexStrToVarBin') IS NULL RAISERROR ('No dbo.HexStrToVarBin installed. Go to http://sqlblog.com/blogs/peter_debetta/archive/2007/03/09/t-sql-convert-hex-string-to-varbinary.aspx and install it in master database' , 18, 1) SET NOCOUNT ONBEGIN TRY DECLARE @dbName VARCHAR(1000), @schemaName VARCHAR(1000), @tableName VARCHAR(1000), @fullBackupName VARCHAR(1000), @undeletedTableName VARCHAR(1000), @sql VARCHAR(MAX), @tableWasTruncated bit; /* THE FIRST LINE ARE OUR INPUT PARAMETERS In this case we're trying to recover Production.Product1 table in AdventureWorks database. My full backup of AdventureWorks database is at e:\AW.bak */ SELECT @dbName = 'AdventureWorks', @schemaName = 'Production', @tableName = 'Product1', @fullBackupName = 'e:\AW.bak', @undeletedTableName = '##' + @tableName + '_Undeleted', @tableWasTruncated = 0, -- copy the structure from original table to a temp table that we'll fill with restored data @sql = 'IF OBJECT_ID(''tempdb..' + @undeletedTableName + ''') IS NOT NULL DROP TABLE ' + @undeletedTableName + ' SELECT *' + ' INTO ' + @undeletedTableName + ' FROM [' + @dbName + '].[' + @schemaName + '].[' + @tableName + ']' + ' WHERE 1 = 0' EXEC (@sql) IF OBJECT_ID('tempdb..#PagesToRestore') IS NOT NULL DROP TABLE #PagesToRestore /* FIND DATA PAGES WE NEED TO RESTORE*/ CREATE TABLE #PagesToRestore ([ID] INT IDENTITY(1,1), [FileID] INT, [PageID] INT, [SQLtoExec] VARCHAR(1000)) -- DBCC PACE statement to run later RAISERROR ('Looking for deleted pages...', 10, 1) -- use T-LOG direct read to get deleted data pages INSERT INTO #PagesToRestore([FileID], [PageID], [SQLtoExec]) EXEC('USE [' + @dbName + '];SELECT FileID, PageID, ''DBCC TRACEON (3604); DBCC PAGE ([' + @dbName + '], '' + FileID + '', '' + PageID + '', 3) WITH TABLERESULTS'' as SQLToExecFROM (SELECT DISTINCT LEFT([Page ID], 4) AS FileID, CONVERT(VARCHAR(100), ' + 'CONVERT(INT, master.dbo.HexStrToVarBin(SUBSTRING([Page ID], 6, 20)))) AS PageIDFROM sys.fn_dblog(NULL, NULL)WHERE AllocUnitName LIKE ''%' + @schemaName + '.' + @tableName + '%'' ' + 'AND Context IN (''LCX_MARK_AS_GHOST'', ''LCX_HEAP'') AND Operation in (''LOP_DELETE_ROWS''))t');SELECT *FROM #PagesToRestore -- if upper EXEC returns 0 rows it means the table was truncated so find truncated pages IF (SELECT COUNT(*) FROM #PagesToRestore) = 0 BEGIN RAISERROR ('No deleted pages found. Looking for truncated pages...', 10, 1) -- use T-LOG read to get truncated data pages INSERT INTO #PagesToRestore([FileID], [PageID], [SQLtoExec]) -- dark magic happens here -- because truncation simply deallocates pages we have to find out which pages were deallocated. -- we can find this out by looking at the PFS page row's Description column. -- for every deallocated extent the Description has a CSV of 8 pages in that extent. -- then it's just a matter of parsing it. -- we also remove the pages in the extent that weren't allocated to the table itself -- marked with '0x00-->00' EXEC ('USE [' + @dbName + '];DECLARE @truncatedPages TABLE(DeallocatedPages VARCHAR(8000), IsMultipleDeallocs BIT);INSERT INTO @truncatedPagesSELECT REPLACE(REPLACE(Description, ''Deallocated '', ''Y''), ''0x00-->00 '', ''N'') + '';'' AS DeallocatedPages, CHARINDEX('';'', Description) AS IsMultipleDeallocsFROM (SELECT DISTINCT LEFT([Page ID], 4) AS FileID, CONVERT(VARCHAR(100), CONVERT(INT, master.dbo.HexStrToVarBin(SUBSTRING([Page ID], 6, 20)))) AS PageID, DescriptionFROM sys.fn_dblog(NULL, NULL)WHERE Context IN (''LCX_PFS'') AND Description LIKE ''Deallocated%'' AND AllocUnitName LIKE ''%' + @schemaName + '.' + @tableName + '%'') t;SELECT FileID, PageID , ''DBCC TRACEON (3604); DBCC PAGE ([' + @dbName + '], '' + FileID + '', '' + PageID + '', 3) WITH TABLERESULTS'' as SQLToExecFROM (SELECT LEFT(PageAndFile, 1) as WasPageAllocatedToTable , SUBSTRING(PageAndFile, 2, CHARINDEX('':'', PageAndFile) - 2 ) as FileID , CONVERT(VARCHAR(100), CONVERT(INT, master.dbo.HexStrToVarBin(SUBSTRING(PageAndFile, CHARINDEX('':'', PageAndFile) + 1, LEN(PageAndFile))))) as PageIDFROM ( SELECT SUBSTRING(DeallocatedPages, delimPosStart, delimPosEnd - delimPosStart) as PageAndFile, IsMultipleDeallocs FROM ( SELECT *, CHARINDEX('';'', DeallocatedPages)*(N-1) + 1 AS delimPosStart, CHARINDEX('';'', DeallocatedPages)*N AS delimPosEnd FROM @truncatedPages t1 CROSS APPLY (SELECT TOP (case when t1.IsMultipleDeallocs = 1 then 8 else 1 end) ROW_NUMBER() OVER(ORDER BY number) as N FROM master..spt_values) t2 )t)t)tWHERE WasPageAllocatedToTable = ''Y''') SELECT @tableWasTruncated = 1 END DECLARE @lastID INT, @pagesCount INT SELECT @lastID = 1, @pagesCount = COUNT(*) FROM #PagesToRestore SELECT @sql = 'Number of pages to restore: ' + CONVERT(VARCHAR(10), @pagesCount) IF @pagesCount = 0 RAISERROR ('No data pages to restore.', 18, 1) ELSE RAISERROR (@sql, 10, 1) -- If the table was truncated we'll read the data directly from data pages without restoring from backup IF @tableWasTruncated = 0 BEGIN -- RESTORE DATA PAGES FROM FULL BACKUP IN BATCHES OF 200 WHILE @lastID <= @pagesCount BEGIN -- create CSV string of pages to restore SELECT @sql = STUFF((SELECT ',' + CONVERT(VARCHAR(100), FileID) + ':' + CONVERT(VARCHAR(100), PageID) FROM #PagesToRestore WHERE ID BETWEEN @lastID AND @lastID + 200 ORDER BY ID FOR XML PATH('')), 1, 1, '') SELECT @sql = 'RESTORE DATABASE [' + @dbName + '] PAGE = ''' + @sql + ''' FROM DISK = ''' + @fullBackupName + '''' RAISERROR ('Starting RESTORE command:' , 10, 1) WITH NOWAIT; RAISERROR (@sql , 10, 1) WITH NOWAIT; EXEC(@sql); RAISERROR ('Restore DONE' , 10, 1) WITH NOWAIT; SELECT @lastID = @lastID + 200 END /* If you have any differential or transaction log backups you should restore them here to bring the previously restored data pages up to date */ END DECLARE @dbccSinglePage TABLE ( [ParentObject] NVARCHAR(500), [Object] NVARCHAR(500), [Field] NVARCHAR(500), [VALUE] NVARCHAR(MAX) ) DECLARE @cols NVARCHAR(MAX), @paramDefinition NVARCHAR(500), @SQLtoExec VARCHAR(1000), @FileID VARCHAR(100), @PageID VARCHAR(100), @i INT = 1 -- Get deleted table columns from information_schema view -- Need sp_executeSQL because database name can't be passed in as variable SELECT @cols = 'select @cols = STUFF((SELECT '', ['' + COLUMN_NAME + '']''FROM ' + @dbName + '.INFORMATION_SCHEMA.COLUMNSWHERE TABLE_NAME = ''' + @tableName + ''' AND TABLE_SCHEMA = ''' + @schemaName + '''ORDER BY ORDINAL_POSITIONFOR XML PATH('''')), 1, 2, '''')', @paramDefinition = N'@cols nvarchar(max) OUTPUT' EXECUTE sp_executesql @cols, @paramDefinition, @cols = @cols OUTPUT -- Loop through all the restored data pages, -- read data from them and insert them into temp table -- which you can then insert into the orignial deleted table DECLARE dbccPageCursor CURSOR GLOBAL FORWARD_ONLY FOR SELECT [FileID], [PageID], [SQLtoExec] FROM #PagesToRestore ORDER BY [FileID], [PageID] OPEN dbccPageCursor; FETCH NEXT FROM dbccPageCursor INTO @FileID, @PageID, @SQLtoExec; WHILE @@FETCH_STATUS = 0 BEGIN RAISERROR ('---------------------------------------------', 10, 1) WITH NOWAIT; SELECT @sql = 'Loop iteration: ' + CONVERT(VARCHAR(10), @i); RAISERROR (@sql, 10, 1) WITH NOWAIT; SELECT @sql = 'Running: ' + @SQLtoExec RAISERROR (@sql, 10, 1) WITH NOWAIT; -- if something goes wrong with DBCC execution or data gathering, skip it but print error BEGIN TRY INSERT INTO @dbccSinglePage EXEC (@SQLtoExec) -- make the data insert magic happen here IF (SELECT CONVERT(BIGINT, [VALUE]) FROM @dbccSinglePage WHERE [Field] LIKE '%Metadata: ObjectId%') = OBJECT_ID('['+@dbName+'].['+@schemaName +'].['+@tableName+']') BEGIN DELETE @dbccSinglePage WHERE NOT ([ParentObject] LIKE 'Slot % Offset %' AND [Object] LIKE 'Slot % Column %') SELECT @sql = 'USE tempdb; ' + 'IF (OBJECTPROPERTY(object_id(''' + @undeletedTableName + '''), ''TableHasIdentity'') = 1) ' + 'SET IDENTITY_INSERT ' + @undeletedTableName + ' ON; ' + 'INSERT INTO ' + @undeletedTableName + '(' + @cols + ') ' + STUFF((SELECT ' UNION ALL SELECT ' + STUFF((SELECT ', ' + CASE WHEN VALUE = '[NULL]' THEN 'NULL' ELSE '''' + [VALUE] + '''' END FROM ( -- the unicorn help here to correctly set ordinal numbers of columns in a data page -- it's turning STRING order into INT order (1,10,11,2,21 into 1,2,..10,11...21) SELECT [ParentObject], [Object], Field, VALUE, RIGHT('00000' + O1, 6) AS ParentObjectOrder, RIGHT('00000' + REVERSE(LEFT(O2, CHARINDEX(' ', O2)-1)), 6) AS ObjectOrder FROM ( SELECT [ParentObject], [Object], Field, VALUE, REPLACE(LEFT([ParentObject], CHARINDEX('Offset', [ParentObject])-1), 'Slot ', '') AS O1, REVERSE(LEFT([Object], CHARINDEX('Offset ', [Object])-2)) AS O2 FROM @dbccSinglePage WHERE t.ParentObject = ParentObject )t)t ORDER BY ParentObjectOrder, ObjectOrder FOR XML PATH('')), 1, 2, '') FROM @dbccSinglePage t GROUP BY ParentObject FOR XML PATH('') ), 1, 11, '') + ';' RAISERROR (@sql, 10, 1) WITH NOWAIT; EXEC (@sql) END END TRY BEGIN CATCH SELECT @sql = 'ERROR!!!' + CHAR(10) + CHAR(13) + 'ErrorNumber: ' + ERROR_NUMBER() + '; ErrorMessage' + ERROR_MESSAGE() + CHAR(10) + CHAR(13) + 'FileID: ' + @FileID + '; PageID: ' + @PageID RAISERROR (@sql, 10, 1) WITH NOWAIT; END CATCH DELETE @dbccSinglePage SELECT @sql = 'Pages left to process: ' + CONVERT(VARCHAR(10), @pagesCount - @i) + CHAR(10) + CHAR(13) + CHAR(10) + CHAR(13) + CHAR(10) + CHAR(13), @i = @i+1 RAISERROR (@sql, 10, 1) WITH NOWAIT; FETCH NEXT FROM dbccPageCursor INTO @FileID, @PageID, @SQLtoExec; END CLOSE dbccPageCursor; DEALLOCATE dbccPageCursor; EXEC ('SELECT ''' + @undeletedTableName + ''' as TableName; SELECT * FROM ' + @undeletedTableName)END TRYBEGIN CATCH SELECT ERROR_NUMBER() AS ErrorNumber, ERROR_MESSAGE() AS ErrorMessage IF CURSOR_STATUS ('global', 'dbccPageCursor') >= 0 BEGIN CLOSE dbccPageCursor; DEALLOCATE dbccPageCursor; ENDEND CATCH-- if the table was deleted we need to finish the restore page sequenceIF @tableWasTruncated = 0BEGIN -- take a log tail backup and then restore it to complete page restore process DECLARE @currentDate VARCHAR(30) SELECT @currentDate = CONVERT(VARCHAR(30), GETDATE(), 112) RAISERROR ('Starting Log Tail backup to c:\Temp ...', 10, 1) WITH NOWAIT; PRINT ('BACKUP LOG [' + @dbName + '] TO DISK = ''c:\Temp\' + @dbName + '_TailLogBackup_' + @currentDate + '.trn''') EXEC ('BACKUP LOG [' + @dbName + '] TO DISK = ''c:\Temp\' + @dbName + '_TailLogBackup_' + @currentDate + '.trn''') RAISERROR ('Log Tail backup done.', 10, 1) WITH NOWAIT; RAISERROR ('Starting Log Tail restore from c:\Temp ...', 10, 1) WITH NOWAIT; PRINT ('RESTORE LOG [' + @dbName + '] FROM DISK = ''c:\Temp\' + @dbName + '_TailLogBackup_' + @currentDate + '.trn''') EXEC ('RESTORE LOG [' + @dbName + '] FROM DISK = ''c:\Temp\' + @dbName + '_TailLogBackup_' + @currentDate + '.trn''') RAISERROR ('Log Tail restore done.', 10, 1) WITH NOWAIT;END-- The last step is manual. Insert data from our temporary table to the original deleted table The misconception here is that you can do a single table restore properly in SQL Server. You can't. But with little experimentation you can get pretty close to it. One way to possible remove a dependency on a backup to retrieve deleted pages is to quickly run a similar script to the upper one that gets data directly from data pages while the rows are still marked as ghost records. It could be done if we could beat the ghost record cleanup task.

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