By mistake I have updated data on production database. Is there any way to rollback those transactions.
I have executed the update statement from management studio and the script does not have in
Begin Trans/rollback/commit.
Thanks
Here is what I would do in this case:
Restore backup in separate database and compare these databases to recover rows that exist in backup?
If your database is in full recovery mode try reading transaction log to recover the remaining rows.
In order to read transaction log you can use a third party tool such as ApexSQL Log or try to do this yourself through fn_dblog function (here is an example but it’s quite complex).
Here are other posts on this topic:
Read the log file (*.LDF) in SQL Server 2008
How can I rollback an UPDATE query in SQL server 2005?
Without transaction (or indeed even with a committed transaction), there is no easy way to revert the changes made.
Transaction are mostly useful to ensure that a series of changes to the database are performed as a single unit, i.e. so that either all of these changes get performed [in the order prescribed] or that none of them get performed at all (or more precisely that the database server rolls-back whatever changes readily done would there be a problem before all changes are completed normaly).
Depending on the recovery model associated with your database, the SQL log file may be of help in one of two ways:
If you have a backup and if the log file was started right after this backup, the logfile may help "roll forward" the database to the point that preceded the unfortunate changes mentioned in the question. (aka point-in-time restore)
If no such backup is avaiable, the log file may be suitable to reverse the unfortunate changes
Both of these approaches imply that the SQL log was indeed maintained as some of the recovery models, are such that the log file get truncated (its data lost) after each successful batch/transaction. And neither of these approaches is easy, the latter in particular probably require third party software (or a lenghty procedure) etc.
Depending on how your backups are set up, you may be able to do a point in time restore. Talk to your DBA. You may also want to take the DB offline ASAP to prevent more changes that would eventually be lost when you do the restore.
Related
I'm using SQL Server 2012 in a local environment. In fact, it is running on my Windows 7 machine. My problem is as follows: I receive a daily backup of my SQL database. Right now, I'm just restoring the whole database on a daily basis by deleting the existing one. This restore task takes quite some time to complete. My understanding of the restore process is that it overwrites the previous database with the new backup.
Is there a way for SQL Server 2012 to just modify the existing database with any changes that have occured in the new backup? I mean, something like comparing the previous database with the updated one and making the necessary changes where needed.
Yes, instead of a full backup you ill need a differential backup. Restore it to move to a "point in time" state of original database.
Make a basic research about full/differential and log backups (too many info for a short answer)
I don't believe so. You can do things with database replication, but that's probably not appropriate.
If you did have something to just pull out changes it might not be faster than a restore anyway. Are you a C# or similar dev? If so, I'd be tempted to write a service which monitored the location of the backup and start the restore programatically when it arrives; might save some time.
If your question is "Can I merge changes from an external DB to my current DB without having to restore the whole DB?" then the answer is "Yes, but not easily." You can set up log shipping, but that's fairly complicated to do automatically. It's also fairly complicated to do manually, but for different reasons: there's no "Microsoft" way to do it. You have to figure out manual log shipping largely on your own.
You could consider copying the tables manually via a Linked Server. If you're only updating a small number of tables this might work just fine, and you could save yourself some trouble. A linked server on your workstation, a few MERGE statements saved to a .sql file, and you could update the important tabled in the DB as you need to.
You can avoid having to run the full backup on the remote server by using differential backups, but it's not particularly pleasant.
My assumption is that currently you're getting a full backup created with the COPY_ONLY option. This allows you to create an out-of-band backup copy that doesn't interfere with existing backups.
To do what you actually want, you'd have to do this: on the server you set up backup to do a full backup on day 1, and then do differential backups on days 2-X. Now, on your local system, you retain the full backup of the DB you created on day 1. You then have all differential backups since day 1. You restore the day 1 full DB, and then restore each subsequent differential in the correct order.
However, differential backups require the backup chain to be intact. You can't use COPY_ONLY with a differential backup. That means if you're also using backup to actually backup the database, you're going to either use these same backups for your data backups, or you'll need to have your data backups using COPY_ONLY, both of which seem philosophically wrong. Your dev database copies shouldn't be driving your prod backup procedures.
So, you can do it, but:
You still have to do a full DB restore.
You have considerably more work to do to restore the DB.
You might break your existing backup procedures of the original DB.
I think the question says it all,
the following update query has been executed - by mistake - in SQL Server management studio
update kms_students set student_campus='4' where student_campus='KL'
The effected rows are more than 1000, and i can't identify it since that table is already have the student_campus='4' for many previous rows.
Is it possible to roll back?
I believe ApexSQL should do the trick.
ApexSQL works by analyzing the physical transaction log which basically has all the necessary info to restore specific transactions and data, but MS doesn't provide an out-of-box tool to manage it, other than restoring a backup and then manually restoring the transaction log up to a particular date using RESTORE LOGS
Backup. Most Hosting companies keep one, try calling everyone asap.
Your own backups. Even if they're old they will be helpful.
Keep lots of Backups and NEVER try out queries on production environment. NEVER.(Bet you learned that, right?)
To make it a bit easier, you can try putting the backup DB online and execute some PHP/Python/whatever so as to compare each record from the Backup and change the current database fom '4' to 'KL' where needed.
May not be perfect, but can help you avoid a few days of work.
Every time I run a query, my database does not respond to an immediate second query and complains that it is in recovery mode (though it does not show anything beside the database name). This happens for about 5-10 minutes after which everything goes back to being normal.
I am expecting a major crash so I am copying the tables into a different database but anyone knows why this could happen or if there is a permanent fix?
Normally, a database is only in "Recovery" mode during startup - when SQL Server starts up the database. If your database goes into Recovery mode because of a SQL statement, you almost definitely have some sort of corruption.
This corruption can take one of many forms and can be difficult to diagnose. Before you do anything, you need to check a few things.
Make sure you have good backups of your database - copied onto a separate file system/server.
Check Windows Event Log and look for errors. If any critical errors are found, contact Microsoft.
Check SQL Server ERRORLOG and look for errors. If any critical errors are found, contact Microsoft.
Run chkdsk on all the hard drives on the server.
Run dbcc checkdb against your database. If any errors are found, you can attempt to fix the database with the REPAIR_REBUILD option. If any errors could not be fixed, contact Microsoft.
Restore a backup copy of your database onto a different server. This will confirm whether it is a problem within your database or the SQL Server/machine.
After step #4, #5, and #6, run your queries again to see if you can cause the database to go into Recovery mode. Unfortunately, corruption can occur because of an untold number of reasons, but more important than anything is the data. It will confirm whether it is a problem with your data or elsewhere. As long as you have backups that can be restored to a different SQL Server and a restored copy does not continually go into Recovery mode, you don't have to worry too much.
I always put Number 6 last because setting up a separate server with SQL Server and moving/restoring a large database can take an extensive amount of time; but if you already have a backup/test server in place, this might be a good first option. After all, it won't cause any downtime with your live server.
Finally, don't be afraid to contact Microsoft over this. Databases are often mission-critical, and Microsoft has plenty of tools at their disposal to diagnose problems just like this.
Late answer...
Does your database have autoclose set to true? When set, the DBMS has to bring the database online which may account for your symptoms
This can happen when the SQL Server Service has gone down hard in the middle of write operations and sometimes during mode during server startup. Follow the query in this link to monitor
http://errorbank.blogspot.com/2012/09/mssql-server-database-in-recovery.html
I've only had this happen when the service (or the SQL Server Service) has gone down hard in the middle of write operations. Once it came back, everything was fine.
However, if this happening often, then I would suspect a disk level failure of some sort. I would make sure the database is fully backed up and move it to another server while you run diagnostics / rebuild the problem server.
How to recover a deleted row from SQL Server 2005 table?
If you have database backups that have deleted data:
Restore backup in separate database and recover deleted data from there
If there are no backups but your database is in full recovery mode:
Try reading transaction log using some third party transaction log
reader or using DBCC LOG command.
You’ll need help from third party tools because transaction log is not well documented. This is because it’s purpose is not to be used for this kind of recovery. However, if you can read it there are a lot of useful details there that can be used to recover accidentally deleted data.
Rollback the transaction (if you started one).
Restore a backup (if you have one).
[edit] If you have transaction logs, you should be able to restore the backup of the database to the point roughly just before the row was deleted (assuming you know when that was).
There are two ways we can recovery specific table:
The first one: restore fullback up with no recovery after restore with no_truncate option for t-log backup
The second way: using triggers we can recovery deleted tables with audit table.
The ApexSQL Log tool can be the solution for deleted rows. In case the DELETE operation exists (the database was not using the Simple recovery model) in database transaction logs (online, backups), the tool can create an undo T-SQL script for the operation.
Disclaimer: I work as a Product Support Engineer at ApexSQL
Don't forget to set full recovery model for a database if you need the "restore to a point in time" option!
I have two MS SQL 2005 servers, one for production and one for test and both have a Recovery Model of Full. I restore a backup of the production database to the test server and then have users make changes.
I want to be able to:
Roll back all the changes made to the test SQL server
Apply all the transactions that have occurred on the production SQL server since the test server was originally restored so that the two servers have the same data
I do not want to do a full database restore from backup file as this takes far too long with our +200GB database especially when all the changed data is less than 1GB.
EDIT
Based on the suggestions below I have tried restoring a database with NoRecovery but you cannot create a snapshot of a database that is in that state.
I have also tried restoring it to Standby Read only mode which works and I can take a snapshot of the database then and still apply transaction logs to the original db but I cannot make the database writable again as long as there are snapshots against it.
Running:
restore database TestDB with recovery
Results in the following error:
Msg 5094, Level 16, State 2, Line 1 The operation cannot be performed on a database with database snapshots or active DBCC replicas
First off, once you've restored the backup and set the database to "recovered", that's it -- you will never be able to apply another transaction log backup to it.
However, there are database snapshots. I've never used them, but I believe you could use them for this purpose. I think you need to restore the database, leave it in "not restored" mode -- definitly not standby -- and then generate snapshots based on that. (Or was that mirroring? I read about this stuff years ago, but never had reason to use it.)
Then when you want to update the database, you drop the snapshot, restore the "next" set of transaction log backups, and create a fresh snapshot.
However, I don't think this would work very well. Above and beyond the management and maintenance overhead of doing this, if the testers/developers do a lot of modifications, your database snapshot could get very big, even bigger than the original database -- and that's hard drive space used in addition to the "original" database. For infrequently modified databases this could work, but for large OLTP systems, I have serious doubts.
So what you really want is a copy of Production to be made in Test. First, you must have a current backup of production somewhere??. Usually on a database this size full backups are made Sunday nights and then differential backups are made each night during the week.
Take the Sunday backup copy and restore it as a different database name on your server, say TestRestore. You should be able to kick this off at 5:00 pm and it should take about 10 hours. If it takes a lot longer see Optimizing Backup and Restore Performance in SQL Server.
When you get in in the morning restore the last differential backup from the previous night, this shouldn't take long at all.
Then kick the users off the Test database and rename Test to TestOld (someone will need something), then rename your TestRestore database to be the Test database. See How to rename a SQL Server Database.
The long range solution is to do log shipping from Production to TestRestore. The at a moments notice you can rename things and have a fresh Test database.
For the rollback, the easiest way is probably using a virtual machine and not saving changes when you close it.
For copying changes across from the production to the test, could you restore the differential backups or transaction log backups from production to the test db?
After having tried all of the suggestions offered here I have not found any means of accomplishing what I outlined in the question through SQL. If someone can find a way and post it or has another suggestion I would be happy to try something else but at this point there appears to be no way to accomplish this.
Storage vendors (as netapp) provide the ability to have writeable snapshots.
It gives you the ability to create a snapshot within seconds on the production, do your tests, and drop/recreate the snapshot.
It's a long term solution, but... It works
On Server1, a job exists that compresses the latest full backup
On Server2, there's a job that performs the following steps:
Copies the compressed file to a local drive
Decompresses the file to make the full backup available
Kills all sessions to the database that is about to be restored
Restores the database
Sets the recovery model to Simple
Grants db_owner privileges to the developers
Ref:http://weblogs.sqlteam.com/tarad/archive/2009/02/25/How-to-refresh-a-SQL-Server-database-automatically.aspx