SQL Monitor stores a large amount of high, medium and low volume data in the Data Repository. To prevent the Data Repository database using all your hard disk space, SQL Monitor checks for old data every hour, and purges data that is older than the time specified for each category in your purging policy.

Configuring data purging

Go to the Configuration tab. Under Data Management, select Data purging:

Data is stored in three separate categories: Machine data, SQL Server data and Alert data. Each category is broken down further to make it easier to identify whether the data could become high, medium or low volume, and where the data is displayed in SQL Monitor. The default purge setting for each type of data is displayed in brackets:

The default purge settings are designed to keep the data you're most interested in for longer without using up too much disk space. To change these settings, select a different time limit from the drop-down list for each category and click Save settings.

How frequently should I purge data?

Your purging frequency depends on:

There is a Do not purge option for each category, which means data will be stored indefinitely in your Data Repository, but you should ensure that you have enough disk space available to accommodate potentially high volumes of data. For more information, see Growth in size of Data Repository database.

What is the effect of purging data?

If you decide to reduce the amount of data being retained, for example reducing Basic Machine Data from 2 months to 2 weeks, then the purge process will require time to process the data. Therefore say that there is 5GB of Basic Machine Data, and a change should reduce that to 3GB, the process needs to identify and delete 2GB of data.