Here’s a scenario that’ll be depressingly familiar to most reading this: after ages of running fine, and no changes to the code, a query suddenly starts running for magnitudes longer than it used to.

In this instance it was an ETL step which used to take c.1 hour, and was now at 5 hours and counting. Since it still hadn’t finished, and the gods had conspired to bring down Grid too (unrelated), I generated a SQL Monitor report to see what was happening: [sourcecode language=“sql”] select DBMS_SQLTUNE.REPORT_SQL_MONITOR( type=>‘HTML’, report_level=>‘ALL’,sql_id=>‘939abmqmvcc4d’) as report FROM dual; [/sourcecode] (h/t to Martin Berger for this)