Dictionary, Fixed Object and System Statistics
When to Gather Dictionary, System, and Fixed Object Statistics (DBMS_STATS) Summary Here I’ll go over the main situations where it makes sense to gather dictionary , system , and fixed object statistics with DBMS_STATS . The idea is not to run these every day like schema stats, but rather in specific scenarios. I’ll also drop some quick PL/SQL snippets you can use straight away. When to gather Dictionary Stats? Dictionary stats don’t need to be refreshed all the time. Honestly, scheduling them daily doesn’t make much sense. But there are a few good moments where gathering them will help the optimizer a lot: After upgrades or patching : new Oracle versions or patches may change dictionary structures. Big schema changes : adding/dropping many objects, indexes, etc. Before new apps go live : especially if they hit metadata queries heavily. Environments with tons of D...
