"Rhys A.D. Stewart" <rhys.stewart@xxxxxxxxx> writes: > I'm using postgres_fdw and am having a pushdown issue. The TL;DR is > that the where clause doesn't get pushed down for the last of the > following three queries. > SELECT * FROM service.mrrdr_synth WHERE premises = '1057430'; > SELECT * FROM service.mrrdr_synth WHERE reading_val = '8'; > SELECT * FROM service.mrrdr_synth WHERE location_capture_time = > '2018-10-20 12:02:53.097247-05'::timestamptz; Well, you've got > CREATE FOREIGN TABLE service.mrrdr_synth( ... > location_capture_time timestamp without time zone NULL, so that WHERE clause is a comparison of timestamp vs timestamptz, which depends on the active timezone setting, so it's not immutable and won't get pushed. (In English: the planner is afraid the remote end might be using a different timezone setting.) I'm pretty sure either timestamp = timestamp or timestamptz = timestamptz would be pushable. regards, tom lane
