I’ve been receiving ORA-1555 (snapshot too old) alerts from my databases via Enterprise Manager 13c. For production environments, these are good alerts to receive and can be an indicator that I have an issue to resolve. For my development databases, ORA-1555 errors are not a concern of mine. It is common for developers to write queries that run a long time and then tune them later on. I do not want to see alerts on ORA-1555 errors in my Inbox from dev databases. Yet EM13c does not have an obvious way to stop these alerts from coming. I recently learned that one can filter out rows of the Alert Log from EM13c’s notification functionality, thus supressing any ORA-1555 alerts from being generated.
To do this, log in to EM13c and navigate to the database in question (or update a template). Then click on Oracle Database –> Monitoring –> Metric and Collection Settings. In the DB Alert Log section is Generic Alert Log Error. Press the pencils icon on the right for this line to edit the settings.
Scroll down to the very bottom of the next page. In the section titled Metric Collection Properties, there is one box labelled Alert Log Filter Expression. This box is a regular expression. Any lines in the Alert Log that match the regex will be filtered out from consideration. As you can see below, I added the “01555” error code.
Not only can you filter out any ORA-1555 errors, but you can see others that can be filtered out as well.