We are migrating to v9.5.1. Migration guide says:

During database migration, the statistics collected for system catalog tables are not retained. You must update the statistics for these tables using the RUNSTATS command.

Do I understand this sentense "update the statistics on the system tables" right? When I asked this question before the answer was yes RUNSTATS on SYSCAT tables:
runstats on SYSCAT tables

What does it mean exactly?
RUNSTATS ON table SYSCAT.<tablename> ... ???

But they are not tables but views.

Thanks

Run it on the underlying tables SYSIBM.*

Andy

Thanks, Andy.

Do I understand it right that runstats should be done for SYSIBM table (not user/application tables)?

You should periodically do runstats on the user/application depending on their volatility. You only need to do runstats on the sysibm tables after major changes to the catalog (or after a migration).

Andy

Thanks for clarification, Andy. I appreciate it.

done it (wrote a script to do runstats on all SYSIBM.tables) but most tables which names don't start with SYS (e.g. SYSIBM.SQLTABLES, SYSIBM.TABLES) are not updatable. Interesting...

That is because they are not tables, they are views.

Andy

Right. While modifying the query I omitted TYPE='T' from WHERE clause so the query was selecting views as well. Good catch. Thank you, Andy