>> I am wondering if we should take the current SQL used by vacuumdb to >> find missing stats and perform direct syscache lookups in C? > > > So....about that. The exiting missing-stats-only queries test for a > corresponding > pg_statistic_ext_data row for any pg_statistic_ext row that meets the > relation filters, > but at this very moment we can restore all types of extended stats _except_ > expressions. > That functionality could make it into 19, but if it doesn't we're going to > have to adjust > vacuumdb to probe pg_statistic_ext.stxkeys for expression indexes and look for > matching stxdexprs elements. I agree that those matches are better done with > syscache lookups, but the SQL that we're treating as a spec might be a moving > target in the near future.
Eventually we will want vacuumdb to use the "ANALYZE (MISSING_STATS)" command directly, rather than the SQL, but until the restore functionality works for extended stats of expressions, we will need to keep those separated. Did I understand that correctly? -- Sami Imseih Amazon Web Services (AWS)
