\o /dev/null \ir include/insert_two_partitions.sql \o SELECT * FROM PUBLIC."two_Partitions"; EXPLAIN (verbose ON, costs off) SELECT * FROM PUBLIC."two_Partitions"; \echo "The following queries should NOT scan two_Partitions._hyper_1_1_chunk" EXPLAIN (verbose ON, costs off) SELECT * FROM PUBLIC."two_Partitions" WHERE device_id = 'dev2'; EXPLAIN (verbose ON, costs off) SELECT * FROM PUBLIC."two_Partitions" WHERE device_id = 'dev'||'2'; EXPLAIN (verbose ON, costs off) SELECT * FROM PUBLIC."two_Partitions" WHERE 'dev'||'2' = device_id; --test integer partition key CREATE TABLE "int_part"(time timestamp, object_id int, temp float); SELECT create_hypertable('"int_part"', 'time', 'object_id', 2); INSERT INTO "int_part" VALUES('2017-01-20T09:00:01', 1, 22.5); INSERT INTO "int_part" VALUES('2017-01-20T09:00:01', 2, 22.5); --check that there are two chunks SELECT * FROM test.show_subtables('int_part'); SELECT * FROM "int_part" WHERE object_id = 1; --make sure this touches only one partititon EXPLAIN (verbose ON, costs off) SELECT * FROM "int_part" WHERE object_id = 1; --TODO: handle this later? --EXPLAIN (verbose ON, costs off) SELECT * FROM "two_Partitions" WHERE device_id IN ('dev2', 'dev21'); \echo "The following shows non-aggregated queries with time desc using merge append" EXPLAIN (verbose ON, costs off)SELECT * FROM PUBLIC."two_Partitions" ORDER BY "timeCustom" DESC NULLS LAST limit 2; --shows that more specific indexes are used if the WHERE clauses "match", uses the series_1 index here. EXPLAIN (verbose ON, costs off)SELECT * FROM PUBLIC."two_Partitions" WHERE series_1 IS NOT NULL ORDER BY "timeCustom" DESC NULLS LAST limit 2; --here the "match" is implication series_1 > 1 => series_1 IS NOT NULL EXPLAIN (verbose ON, costs off)SELECT * FROM PUBLIC."two_Partitions" WHERE series_1 > 1 ORDER BY "timeCustom" DESC NULLS LAST limit 2; --note that without time transform things work too EXPLAIN (verbose ON, costs off)SELECT "timeCustom" t, min(series_0) FROM PUBLIC."two_Partitions" GROUP BY t ORDER BY t DESC NULLS LAST limit 2; --TODO: time transform doesn't work EXPLAIN (verbose ON, costs off)SELECT "timeCustom"/10 t, min(series_0) FROM PUBLIC."two_Partitions" GROUP BY t ORDER BY t DESC NULLS LAST limit 2; EXPLAIN (verbose ON, costs off)SELECT "timeCustom"%10 t, min(series_0) FROM PUBLIC."two_Partitions" GROUP BY t ORDER BY t DESC NULLS LAST limit 2;