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207391bc54
Since the parent table of a hypertable cannot contain any rows including it in the plan is not necessary. PostgreSQL might also not have good statistics for the main table as autoanalyze is triggered by inserts which never happen to the main table, leading to worse plans. This patch adds a new guc enable_constraint_exclusion to disable planner constraint exclusion. Constraint exclusion will not work with cursors and WHERE CURRENT OF so the new guc will allow you to disable that feature. This patch also fixes constraint exclusion for JOINs and sort optimization for queries with chunks_in.
38 lines
1.6 KiB
SQL
38 lines
1.6 KiB
SQL
-- This file and its contents are licensed under the Apache License 2.0.
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-- Please see the included NOTICE for copyright information and
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-- LICENSE-APACHE for a copy of the license.
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--
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\set PREFIX 'EXPLAIN (COSTS OFF) '
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CREATE TABLE order_test(time int NOT NULL, device_id int, value float);
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CREATE INDEX ON order_test(time,device_id);
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CREATE INDEX ON order_test(device_id,time);
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SELECT create_hypertable('order_test','time',chunk_time_interval:=1000);
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INSERT INTO order_test SELECT 0,10,0.5;
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INSERT INTO order_test SELECT 1,9,0.5;
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INSERT INTO order_test SELECT 2,8,0.5;
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-- we want to see here that index scans are possible for the chosen expressions
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-- so we disable seqscan so we dont need to worry about other factors which would
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-- make PostgreSQL prefer seqscan over index scan
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SET enable_seqscan TO off;
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-- test sort optimization with single member order by
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SELECT time_bucket(10,time),device_id,value FROM order_test ORDER BY 1;
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-- should use index scan
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:PREFIX SELECT time_bucket(10,time),device_id,value FROM order_test ORDER BY 1;
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-- test sort optimization with ordering by multiple columns and time_bucket not last
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SELECT time_bucket(10,time),device_id,value FROM order_test ORDER BY 1,2;
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-- must not use index scan
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:PREFIX SELECT time_bucket(10,time),device_id,value FROM order_test ORDER BY 1,2;
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-- test sort optimization with ordering by multiple columns and time_bucket as last member
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SELECT time_bucket(10,time),device_id,value FROM order_test ORDER BY 2,1;
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-- should use index scan
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:PREFIX SELECT time_bucket(10,time),device_id,value FROM order_test ORDER BY 2,1;
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