On Tue, 2019-10-29 at 22:11 -0700, Wells Oliver wrote: > I just upgraded from 9.6 to 12, and am noticing some queries are slow. > > I did this kind of query: > > SELECT relname, last_vacuum, last_autovacuum, last_analyze, last_autoanalyze > FROM pg_stat_all_tables > WHERE schemaname = 'myschema'; > > And noticed null values for everything, including last analyze date. > > Does this mean the planner won't be able to optimize for these tables? > Do I need to do something to prep my DB for planning after upgrade? You used pg_upgrade, right? pg_upgrade won't migrate any table statistics. You'll have to run ANALYZE to collect new ones. This is even mentioned in the output of pg_upgrade, and it writes a convenient shell script that does the ANALYZE for you. Yours, Laurenz Albe -- Cybertec | https://www.cybertec-postgresql.com