Consider the following scenario:
You have configured Microsoft SQL Server 2012 Reporting Services (SSRS 2012) or SQL Server 2014 Reporting Services (SSRS 2014) to run in SharePoint Integrated mode.
You have installed Microsoft SharePoint Server 2013 or Microsoft SharePoint Server 2010 on your computer.
You have created some data alerts for some reports in your SharePoint site.
In this scenario, you notice that the alerting database is very big. That is because there are many rows in the FeedData and FeedPool tables of the alerting database. Also, the alerting database does not clean up data that was created more than 180 days ago.
Note By default, Reporting Service retains the alert data of the past 180 days. The retention time of the alert data depends on the value of the AlertingMaxDataRetentionDays key that is set in the Rsreportserver.config file. By default, the Rsreportserver.config file is located in the following path:
<Drive>\Program Files\Common Files\Microsoft Shared\Web Server Extensions\<SharePoint Version Number>\WebServices\Reporting\
Cumulative Update information
This issue was first fixed in the following cumulative update of SQL Server.
Each new cumulative update for SQL Server contains all the hotfixes and all the security fixes that were included with the previous cumulative update. We recommend that you download and install the latest cumulative updates for SQL Server:
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.