from your experience do you ever REORG system tables (SYSIBM.*)? in what situations?
thanks

doveryai, no proveryai

I don't recall ever doing a reorg on the catalog at our shop (mainframe), but that is most likely because we didn't do a lot of changes to the catalog... or could be some other reason. I don't remember.

I think it's a good idea to reorg your system catalog tables after a significant schema change and reorgchk can help you decide what to reorg. If you're going to reorg, then do runstats as well.

we don't manually run reorgchk - we have to run maintanence script to reorg and runstats all tables in production within a small maintanence window. i think i will exclude system tables from reorg and runstats all tables incl. system.

thank you, Bella

It depends... if your database or subsystem has a lot of tables and/or columns (a lot means a few thousand), I would consider system tables for reorg. Especially if you have page locks, it can be beneficial.

If the schema doesn't change or doesn't change significantly, it should be a one-time task only.

I suggest you put reorging system tables into your schedule. It cost you little time but save you from a lot of problems.

thanks everyone