By default, Reporting Server (SSRS) keeps report execution information in the execution log (‘[dbo].[ExecutionLogStorage]‘). After that, you guessed it…it will be deleted. In case you would like to increase the retention period on this table, there’s a server property named “ExecutionLogDaysKept” for Reporting Services. This can help you to increase the retention period, for more information:
The number of days to keep report execution information in the execution log. Valid values for this property include 0 through 2,147,483,647. If the value is 0 entries are not deleted from the Execution Log table. The default value is 60.
How to increase the number of days
You can modify the settings by connecting to your SSRS database and executing the SetConfigurationInfo stored procedure:
EXEC SetConfigurationInfo @Name=N'ExecutionLogDaysKept',@Value=N'90'
Or connect to your Reporting Services instance with SSMS and open the Server Properties of SSRS and go to ‘Logging’: