mirror of
https://github.com/MariaDB/server.git
synced 2025-01-16 03:52:35 +01:00
113 lines
2.9 KiB
Text
113 lines
2.9 KiB
Text
# Embedded doesn't have optimizer trace:
|
|
--source include/not_embedded.inc
|
|
--source include/have_sequence.inc
|
|
|
|
--echo #
|
|
--echo # MDEV-30660 COUNT DISTINCT seems unnecessarily slow when run on a PK
|
|
--echo #
|
|
|
|
#Enable after fix MDEV-32034
|
|
--disable_view_protocol
|
|
set @save_optimizer_trace = @@optimizer_trace;
|
|
SET optimizer_trace='enabled=on';
|
|
let $trace=
|
|
SELECT JSON_DETAILED(JSON_EXTRACT(trace, '\$**.prepare_sum_aggregators')) AS JS
|
|
FROM INFORMATION_SCHEMA.OPTIMIZER_TRACE;
|
|
|
|
CREATE TABLE t1 (a INT NOT NULL PRIMARY KEY, b INT NOT NULL);
|
|
INSERT INTO t1 VALUES (1,1), (2,1), (3,1);
|
|
|
|
--echo # Optimization is applied (aggregator=simple):
|
|
SELECT COUNT(DISTINCT a) FROM t1;
|
|
eval $trace;
|
|
|
|
SELECT AVG(DISTINCT a), SUM(DISTINCT b) FROM t1;
|
|
eval $trace;
|
|
|
|
--echo # Only `a` is unique but it's enough to eliminate DISTINCT:
|
|
SELECT COUNT(DISTINCT b, a) FROM t1;
|
|
eval $trace;
|
|
|
|
SELECT COUNT(DISTINCT a, a + b) FROM t1;
|
|
eval $trace;
|
|
|
|
SELECT SUM(DISTINCT a), AVG(DISTINCT a), COUNT(DISTINCT a) FROM t1 WHERE a > 1;
|
|
eval $trace;
|
|
|
|
--echo # Optimization is not applied 'cause function argument is not a field
|
|
--echo # (aggregator=distinct):
|
|
SELECT SUM(DISTINCT a + b) FROM t1;
|
|
eval $trace;
|
|
|
|
SELECT COUNT(DISTINCT b) FROM t1;
|
|
eval $trace;
|
|
|
|
SELECT AVG(DISTINCT b / a) FROM t1;
|
|
eval $trace;
|
|
|
|
EXPLAIN SELECT COUNT(DISTINCT (SELECT a)) FROM t1;
|
|
eval $trace;
|
|
|
|
CREATE TABLE t2 (a INT);
|
|
INSERT INTO t2 VALUES (1), (2);
|
|
|
|
--echo # Optimization is not applied 'cause there is more than one table
|
|
SELECT COUNT(DISTINCT t1.a) FROM t1, t2;
|
|
eval $trace;
|
|
|
|
SELECT AVG(DISTINCT t1.a) FROM t1, t2;
|
|
eval $trace;
|
|
|
|
--echo # Const tables, optimization is applied
|
|
SELECT COUNT(DISTINCT a) FROM t1, (SELECT 1) AS t2;
|
|
eval $trace;
|
|
|
|
SELECT AVG(DISTINCT t1.a) FROM (SELECT 1 AS a) AS t2, t1, (SELECT 2 AS a) AS t3;
|
|
eval $trace;
|
|
|
|
SELECT COUNT(DISTINCT a) FROM t1, (SELECT 1 UNION SELECT 2) AS t2;
|
|
eval $trace;
|
|
|
|
--echo # Unique index on two columns
|
|
CREATE TABLE t3 (a INT NOT NULL, b INT NOT NULL);
|
|
INSERT INTO t3 VALUES (1,1), (1,2), (1,3), (2,1), (2,2), (3,1), (3,2);
|
|
CREATE UNIQUE INDEX t3_a_b ON t3 (a, b);
|
|
--echo # Optimization is applied:
|
|
SELECT COUNT(DISTINCT a, b) FROM t3;
|
|
eval $trace;
|
|
|
|
SELECT COUNT(DISTINCT b, a) FROM t3;
|
|
eval $trace;
|
|
|
|
SELECT COUNT(DISTINCT b, a) FROM t3 WHERE a < 3;
|
|
eval $trace;
|
|
|
|
--echo # Optimization is applied to one of the functions:
|
|
SELECT COUNT(DISTINCT b), SUM(DISTINCT a), SUM(DISTINCT a + b) FROM t3 GROUP BY a;
|
|
eval $trace;
|
|
|
|
--echo # Can't apply optimization 'cause GROUP BY argument is not a field:
|
|
SELECT COUNT(DISTINCT b) FROM t3 GROUP BY a+b;
|
|
eval $trace;
|
|
|
|
--echo # Test merged view
|
|
CREATE VIEW v1 AS SELECT * FROM t1;
|
|
--echo # Optimization is applied
|
|
SELECT COUNT(DISTINCT a, b) FROM v1;
|
|
eval $trace;
|
|
|
|
--echo # GROUP_CONCAT implements non-standard distinct aggregator
|
|
SELECT GROUP_CONCAT(b) FROM t1;
|
|
eval $trace;
|
|
|
|
SELECT GROUP_CONCAT(DISTINCT b) FROM t1;
|
|
eval $trace;
|
|
|
|
DROP TABLE t1, t2, t3;
|
|
DROP VIEW v1;
|
|
SET optimizer_trace = @save_optimizer_trace;
|
|
--enable_view_protocol
|
|
|
|
--echo #
|
|
--echo # end of 10.5 tests
|
|
--echo #
|