Manual database clean-up
When we are using an external high volume database, the out-of-the-box periodic clean-up threads can be disabled in order to have fine control over when clean-up is performed. For example, running clean-up only between the hours of 1am - 4am when traffic on the services is low. Note that incorrect clean-up can cause data-loss and functional issues. It is not recommended unless a database admin (DBA) is involved. There are five features that supports clean-up threads:
- Distributed Map
- Context-based access session
- OAuth Tokens
- Authentication service
- Mobile Multi-Factor Authenticator
The periodic clean-up threads run on an interval set in advanced configuration settings. Use these settings to disable periodic cleanup. When we are performing the clean-up, it is essential that database locks are efficient to stop contention. The recommended pattern is to open a read-only cursor on the statement. It identifies rows to be deleted and reuses the cursor to perform the deletion one row at a time. This minimizes the size and duration of the write lock. To achieve this pattern two queries are provided for each table:
- A select pattern. This pattern returns a list of IDs that needs to be deleted.
- A delete query.
How and when these two patterns are run is environment dependent. The discretion and direction of a database admin is recommended. It is also important to manage the commit frequency as some DBMSs have limits. The database admin might be required to supplement some values from the built-in functions.
- Distributed Map Clean-Up
- Context-based access clean-up
- OAuth token clean-up
- Authentication service clean-up
- Mobile Multi-Factor Authentication (MMFA) clean-up
Parent topic: Runtime database