Task #884
Updated by Aaron Marcuse-Kubitza over 10 years ago
h3. issue * see the following @pg_stat_activity@ snapshot taken at 2014-4-2 11:42am PT (note especially the @EXPLAIN@ output below @query_start@ times above each query): <pre><code class="SQL"> snapshot taken: "Apr 2 11:42:26 2014" "query_start" "2014-04-02 06:20:01.952174-07" /*NVS.StemObservation*/ CREATE TEMP TABLE "stemobservation_pkeys" AS SELECT "in#11"."row_num" , "stemobservation"."stemobservation_id" AS "out.stemobservation_id" FROM "in#11" JOIN "stemobservation" ON COALESCE("stemobservation"."height_m", CAST('NaN' AS double precision)) = COALESCE("in#11"."NVS.StemObservation.Height::double", CAST('NaN' AS double precision)) /* EXPLAIN: Merge Join (cost=1045217.21..95909185.15 rows=6323041431 width=8) Merge Cond: ((COALESCE(stemobservation.height_m, 'NaN'::double precision)) = (COALESCE("in#11"."NVS.StemObservation.Height::double", 'NaN'::double precision))) -> Sort (cost=30039.56..30492.76 rows=181279 width=12) Sort Key: (COALESCE(stemobservation.height_m, 'NaN'::double precision)) -> Seq Scan on stemobservation (cost=0.00..14206.79 rows=181279 width=12) -> Materialize (cost=1015177.64..1050057.81 rows=6976033 width=12) -> Sort (cost=1015177.64..1032617.73 rows=6976033 width=12) Sort Key: (COALESCE("in#11"."NVS.StemObs "query_start" "2014-04-01 14:56:05.573418-07" /*CVS.taxon_observation.***/ CREATE TEMP TABLE "location_pkeys" AS SELECT "in#5"."row_num" , "location"."location_id" AS "out.location_id" FROM "in#5" JOIN "location" ON ("location"."accesslevel" = "in#5"."CVS.taxon_observation.**.accessRights::accesslevel" OR ("location"."accesslevel" IS NULL AND "in#5"."CVS.taxon_observation.**.accessRights::accesslevel" IS NULL)) /* EXPLAIN: Nested Loop (cost=0.00..83049883712.45 rows=27683225000 width=8) Join Filter: ((location.accesslevel = "in#5"."CVS.taxon_observation.**.accessRights::accesslevel") OR ((location.accesslevel IS NULL) AND ("in#5"."CVS.taxon_observation.**.accessRights::accesslevel" IS NULL))) -> Seq Scan on location (cost=0.00..175778.45 rows=5536645 width=8) -> Materialize (cost=0.00..35434.00 rows=1000000 width=8) -> Seq Scan on "in#5" (cost=0.00..30434.00 rows=1000000 width=8) */ </code></pre> h3. fix * set query planner settings to prevent it from using sorts where they shouldn't be used