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Better optimize queries that use parameters in the LIMIT clause.

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FossilOrigin-Name: e58cb304d1e0ec6e30260a165aaccc2cf096ce6c999efb06683c4ef600ee12ef
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drh
2024-06-06 15:03:16 +00:00
parent 404ddadbd4
commit 4703b7d092
12 changed files with 156 additions and 29 deletions
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test/wherelimit3.test Normal file
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# 2024-06-06
#
# The author disclaims copyright to this source code. In place of
# a legal notice, here is a blessing:
#
# May you do good and not evil.
# May you find forgiveness for yourself and forgive others.
# May you share freely, never taking more than you give.
#
#***********************************************************************
#
# Test cases for query plans using LIMIT
#
set testdir [file dirname $argv0]
source $testdir/tester.tcl
set testprefix wherelimit3
do_execsql_test 1.0 {
CREATE TABLE t1(a INT, b INT);
WITH RECURSIVE c(n) AS (VALUES(1) UNION ALL SELECT n+1 FROM c WHERE n<1000)
INSERT INTO t1 SELECT n, n FROM c;
CREATE INDEX t1a ON t1(a);
CREATE INDEX t1b ON t1(b);
ANALYZE;
}
do_eqp_test 1.1 {
SELECT * FROM t1 WHERE a>=100 AND a<300 ORDER BY b LIMIT 5;
} {
QUERY PLAN
|--SEARCH t1 USING INDEX t1a (a>? AND a<?)
`--USE TEMP B-TREE FOR ORDER BY
}
ifcapable stat4 {
do_eqp_test 1.2 {
SELECT * FROM t1 WHERE a>=100 AND a<300 ORDER BY b LIMIT -1;
} {
QUERY PLAN
`--SCAN t1 USING INDEX t1b
}
}
set N [expr 5]
do_eqp_test 1.3 {
SELECT * FROM t1 WHERE a>=100 AND a<300 ORDER BY b LIMIT $::N;
} {
QUERY PLAN
|--SEARCH t1 USING INDEX t1a (a>? AND a<?)
`--USE TEMP B-TREE FOR ORDER BY
}
ifcapable stat4 {
set N [expr -1]
do_eqp_test 1.4 {
SELECT * FROM t1 WHERE a>=100 AND a<300 ORDER BY b LIMIT $::N;
} {
QUERY PLAN
`--SCAN t1 USING INDEX t1b
}
}
finish_test