Mariel Cherkassky wrote: > I was testing pgstattuple and I realized that pgstattuple is working on toasted table but pgstattuple_approx is raising the next error msg : > > ERROR: "pg_toast_18292" is not a table or materialized view > > ahm, is that because the pgstattuple_approx uses visibility map ? Can someone explain ? tnx. You are right; here is the code: /* * We support only ordinary relations and materialised views, because we * depend on the visibility map and free space map for our estimates about * unscanned pages. */ if (!(rel->rd_rel->relkind == RELKIND_RELATION || rel->rd_rel->relkind == RELKIND_MATVIEW)) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("\"%s\" is not a table or materialized view", RelationGetRelationName(rel)))); Yours, Laurenz Albe -- Cybertec | https://www.cybertec-postgresql.com