mirror of
https://github.com/timescale/timescaledb.git
synced 2025-05-16 18:43:18 +08:00
425cdd16e4
Construct "SELECT DISTINCT target_list" or "SELECT DISTINCT ON (col1, col..) target_list" statement to push down the DISTINCT clause to the remote side. We only allow references to basic "Vars" or constants in the DISTINCT exprs So, "SELECT DISTINCT col1" is fine but "SELECT DISTINCT 2*col1" is not. "SELECT DISTINCT col1, 'const1', NULL, col2" which is a mix of column references and constants is also supported. Everything else is not supported. This pushdown also needs to work when timescaledb.enable_per_data_node_queries is disabled. All existing test cases in which "SELECT DISTINCT" is now being pushed down have been modified. New test cases have been added to check that the remote side uses "Skip Scans" as is suitable in some cases.
44 lines
1.8 KiB
SQL
44 lines
1.8 KiB
SQL
-- This file and its contents are licensed under the Timescale License.
|
|
-- Please see the included NOTICE for copyright information and
|
|
-- LICENSE-TIMESCALE for a copy of the license.
|
|
|
|
\set TEST_BASE_NAME dist_distinct
|
|
-- Run
|
|
SELECT format('include/%s_run.sql', :'TEST_BASE_NAME') AS "TEST_QUERY_NAME",
|
|
format('%s/shared/results/%s_results_reference.out', :'TEST_OUTPUT_DIR', :'TEST_BASE_NAME') AS "TEST_RESULTS_REFERENCE",
|
|
format('%s/shared/results/%s_results_distributed.out', :'TEST_OUTPUT_DIR', :'TEST_BASE_NAME') AS "TEST_RESULTS_DIST"
|
|
\gset
|
|
SELECT format('\! diff -u --label "Distributed results" --label "Local results" %s %s', :'TEST_RESULTS_DIST', :'TEST_RESULTS_REFERENCE') AS "DIFF_CMD_DIST"
|
|
\gset
|
|
|
|
\set PREFIX 'EXPLAIN (verbose, costs off)'
|
|
\set ORDER_BY_1 'ORDER BY 1'
|
|
\set ORDER_BY_1_2 'ORDER BY 1,2'
|
|
|
|
\set ECHO queries
|
|
-- Get EXPLAIN output for the multi-node environment
|
|
\set TABLE_NAME 'metrics_dist'
|
|
\ir :TEST_QUERY_NAME
|
|
|
|
-- get results for all the queries
|
|
-- run queries on single node hypertable and store result
|
|
-- then run queries on multinode hypertable and store result
|
|
\set PREFIX ''
|
|
\set ECHO none
|
|
SET client_min_messages TO error;
|
|
|
|
-- run queries on single node hypertable and store reference result
|
|
\set TABLE_NAME 'metrics'
|
|
\o :TEST_RESULTS_REFERENCE
|
|
\ir :TEST_QUERY_NAME
|
|
|
|
-- run queries on multinode hypertable and store result
|
|
\set TABLE_NAME 'metrics_dist'
|
|
\o :TEST_RESULTS_DIST
|
|
\ir :TEST_QUERY_NAME
|
|
\o
|
|
\set ECHO all
|
|
|
|
-- diff distributed and reference results (should be exactly same)
|
|
:DIFF_CMD_DIST
|