Auto shrink database property in SQL server allows to automatically shrink the database files if the value is set to ON/True.
However, it is not a good practice to shrink a database. Because it is a very expensive operation in terms of I/O, CPU usage, locking, and transaction log generation.
It is only recommended to shrink the database in cases like data deletion. That is we can run the shrink operation if we’ve deleted some portion of the data to retrieve that space back. Also, we need to ensure that we rebuild the fragmented indexes post performing the shrink operation because this can cause index fragmentation.
Here at Bobcares, we receive requests from customers relating to AutoShrink property in SQL as part of our Server Management Services.
Why we must not enable Auto shrink database property in SQL server
Here are the different reasons why the auto shrink property must not be enabled for the database.
- It will cause index fragmentation which in return reduces the database performance.
- Shrink operation takes a lot of IO and CPU resources. As a result, it may cause long disk queue lengths and possibly IO timeouts.
- Repeatedly shrinking and growing the data files will cause file-system level fragmentation. As a result, it will slow down performance.
- Growing the database in small increments or growing it and then shrinking can cause disk fragmentation. This can cause performance issues.
- It slows down the database server. Because shrinking is a heavy load operation that would take a long time to complete.
- It is unpredictable. Because the Autoshrink operation can start at any time, maybe during the peak time.
How to enable or disable the AutoShrink operation in SQL Server.
Now let’s take a look at how our Support Engineers enable and disable the AutoShrink database property.
- We can turn it On or Off using the SQL Server Management Studio or T-SQL code.
- First, we right-click on the database for which we need to enable or disable the AutoShrink. Then we choose the Properties.
- Next, on the Database Properties window, we click on the Options from the left side pane.
- Now, we can see the AutoShrink option on the right side of the pane. If we wish to turn it On/Off we can click on the drop-down of the option and select True/False.
Here is the T-SQL code to enable or disable the AutoShrink option for any database.
Set Auto Shrink ON or True
ALTER DATABASE DBName SET AUTO_SHRINK ON
Set Auto Shrink OFF or False
ALTER DATABASE DBName SET AUTO_SHRINK OFF
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In short, it is not recommended to enable the AutoShrink database property as it can cause many issues in the SQL Server. Today, we discussed what happens if enable this property. Also, we saw how our Support Engineers enable and disable this database property.