If you have many file growths in your log files, you may have an excessively large number of virtual log files (VLF). If you run a large transaction that requires the log to grow, other transactions that require a write to the transaction log will also have to wait until the grow operation completes. The same sort of issue can result from an autogrow of the data portion of your database. If the growth increment is large or there is some other factor that causes it to take a long time, the query in which you open the transaction might fail because of a timeout error. If you run a transaction that requires more log space than is available, and you have turned on the autogrow option for the transaction log of that database, then the time it takes the transaction to complete will include the time it takes the transaction log to grow by the configured amount. This can prevent frequent shrink and growth of the database files. Leave the unused space in the database files if you think the application usage patterns will need them again. The AUTO_SHRINK background task will need to acquire locks and other synchronization that can conflict with other regular application activity.Ĭonsider setting databases to a required size and pre-grow them. The AUTO_SHRINK background task can take up resources when there are many databases that need shrinking. This is true whether you use the automatic settings or whether you manually grow and shrink the files frequently.Īfter AUTO_SHRINK successfully shrinks the data or log file, a subsequent DML or DDL operation can slow down significantly if space is required and the files need to grow. This can have a severe impact on performance. If multiple databases undergo frequent shrink and grow operations, then this will easily lead to file system level fragmentation. Frequent grow and shrink operations can lead to various performance problems. You have to carefully evaluate setting this option for the databases in a SQL Server instance. This background task evaluates all databases that satisfy the criteria for shrinking and shrink the data or log files. When you enable this option for a database, this database becomes eligible for shrinking by a background task. Depending on your environment, you may end with different settings for each database file.ĪUTO_SHRINK is a database option in SQL Server. If you have multiple data and/or log files, you must set the options on each file. Therefore, you have to set them in at least two places for each database (one for the primary data file and one for the primary log file). Keep in mind that the autogrow settings are per file. To view the current settings, run the following Transact-SQL command: sp_helpdb 'name' ] You can also configure the autogrow option when you create a database. For more information about how to set these settings at database file level, see Add Data or Log Files to a Database.
0 Comments
Leave a Reply. |