Hi, on a PostGIS system tuned for preferring parallelism heavily ( min_parallel_table_scan_size=10kB) we experience issues with QGIS table discovery query with this patch:
Failing query is: [local] gis@gis=# SELECT l.f_table_name,l.f_table_schema,l.f_geometry_column,upper(l.type),l.srid,l.coord_dimension,c.relkind,obj_description(c.oid) FROM geometry_columns l,pg_class c,pg_namespace n WHERE c.relname=l.f_table_name AND l.f_table_schema=n. nspname AND n.oid=c.relnamespace AND has_schema_privilege(n.nspname,'usage') AND has_table_privilege('"'||n.nspname||'"."'||c.relname||'"','select') AND l.f_table_schema='public' ORDER BY n.nspname,c.relname,l.f_geometry_column; ERROR: XX000: badly formatted node string "INCREMENTALSORT :startup_cost 37"... CONTEXT: parallel worker LOCATION: parseNodeString, readfuncs.c:2693 Time: 42,052 ms Query plan: QUERY PLAN ────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────── Sort (cost=38717.21..38717.22 rows=1 width=393) Sort Key: c_1.relname, a.attname -> Nested Loop (cost=36059.35..38717.20 rows=1 width=393) -> Index Scan using pg_namespace_nspname_index on pg_namespace n (cost=0.28..2.30 rows=1 width=68) Index Cond: (nspname = 'public'::name) Filter: has_schema_privilege((nspname)::text, 'usage'::text) -> Nested Loop (cost=36059.08..38714.59 rows=1 width=407) -> Nested Loop Left Join (cost=36058.65..38712.12 rows=1 width=334) Join Filter: ((s_2.connamespace = n_1.oid) AND (a.attnum = ANY (s_2.conkey))) -> Nested Loop Left Join (cost=36058.51..38711.94 rows=1 width=298) Join Filter: ((s_1.connamespace = n_1.oid) AND (a.attnum = ANY (s_1.conkey))) -> Nested Loop (cost=36058.38..38711.75 rows=1 width=252) Join Filter: (a.atttypid = t.oid) -> Gather Merge (cost=36057.95..38702.65 rows=444 width=256) Workers Planned: 10 -> Merge Left Join (cost=35057.76..37689.01 rows=44 width=256) Merge Cond: ((n_1.oid = s.connamespace) AND (c_1.oid = s.conrelid)) Join Filter: (a.attnum = ANY (s.conkey)) -> Incremental Sort (cost=37687.19..37687.30 rows=44 width=210) Sort Key: n_1.oid, c_1.oid Presorted Key: n_1.oid -> Nested Loop (cost=34837.25..37685.99 rows=44 width=210) -> Merge Join (cost=34836.82..34865.99 rows=9 width=136) Merge Cond: (c_1.relnamespace = n_1.oid) -> Sort (cost=34834.52..34849.05 rows=5814 width=72) Sort Key: c_1.relnamespace -> Parallel Seq Scan on pg_class c_1 (cost=0.00..34470.99 rows=5814 width=72) Filter: ((relname <> 'raster_columns'::name) AND (NOT pg_is_other_temp_schema(relnamespace)) AND has_table_privilege(oid, 'SELECT'::text) AND (relkind = ANY ('{r,v,m,f,p}'::"char"[]))) -> Sort (cost=2.30..2.31 rows=1 width=68) Sort Key: n_1.oid -> Index Scan using pg_namespace_nspname_index on pg_namespace n_1 (cost=0.28..2.29 rows=1 width=68) Index Cond: (nspname = 'public'::name) -> Index Scan using pg_attribute_relid_attnum_index on pg_attribute a (cost=0.43..200.52 rows=11281 width=78) Index Cond: (attrelid = c_1.oid) Filter: (NOT attisdropped) -> Sort (cost=1.35..1.35 rows=1 width=77) Sort Key: s.connamespace, s.conrelid -> Seq Scan on pg_constraint s (cost=0.00..1.34 rows=1 width=77) Filter: (consrc ~~* '%geometrytype(% = %'::text) -> Materialize (cost=0.42..2.45 rows=1 width=4) -> Index Scan using pg_type_typname_nsp_index on pg_type t (cost=0.42..2.44 rows=1 width=4) Index Cond: (typname = 'geometry'::name) -> Index Scan using pg_constraint_conrelid_index on pg_constraint s_1 (cost=0.14..0.16 rows=1 width=77) Index Cond: (conrelid = c_1.oid) Filter: (consrc ~~* '%ndims(% = %'::text) -> Index Scan using pg_constraint_conrelid_index on pg_constraint s_2 (cost=0.14..0.16 rows=1 width=77) Index Cond: (conrelid = c_1.oid) Filter: (consrc ~~* '%srid(% = %'::text) -> Index Scan using pg_class_relname_nsp_index on pg_class c (cost=0.42..2.46 rows=1 width=73) Index Cond: ((relname = c_1.relname) AND (relnamespace = n.oid)) Filter: has_table_privilege((((('"'::text || (n.nspname)::text) || '"."'::text) || (relname)::text) || '"'::text), 'select'::text) (51 rows) Darafei Praliaskouski, GIS Engineer / Juno Minsk