How to shrink SQL / SharePoint database / log files

1. First to be on the safe side, let’s back it up (this step is optional)

Select New Query

Type the following:

BACKUP LOG [Sharepoint_Config] TO DISK='D:\SharePointConfigLogBackup.bak'
GO

Where SharePoint_Config is the name of your config database file and D:\SharePoinConfiglogbackup.bak is the location and file name of where you’ll make the backup.

And click Execute

2. Use the following simple three steps to shrink your database

USE [master]  

GO  

ALTER DATABASE [SharePoint_Config] SET RECOVERY SIMPLE WITH NO_WAIT  

GO  

Click Execute

USE [Sharepoint_Config]  

GO  

DBCC SHRINKFILE ('SharePoint_Config_log')  

GO  

Click Execute

ALTER DATABASE [SharePoint_Config] SET RECOVERY FULL WITH NO_WAIT 

GO

USE [Sharepoint_Config]  

GO

Click Execute

3. If you get the below error when you run the shrink file query

Msg 8985, Level 16, State 1, Line 1

Could not locate file 'tempdb_log' for database 'tempdb' in sys.database_files. The file either does not exist, or was dropped. 

Use the below commends to shrink those system database files

USE tempdb;

GO

SELECT file_id, name FROM sys.database_files;

GO

DBCC SHRINKFILE (2, TRUNCATEONLY);

Here tempdb is your system database files name.