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Add a test case to show that ticket [e8b674241947eb3b] has been fixed.

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FossilOrigin-Name: e20de6d450c2b4d5bde737f625de16ff53262c22ce7aa6917b64f1665170d33f
This commit is contained in:
drh
2022-12-03 17:23:29 +00:00
parent e4fa4794be
commit fcf4243c36
3 changed files with 39 additions and 7 deletions
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32
test/sort.test
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@ -595,4 +595,36 @@ do_execsql_test 17.1 {
SELECT * FROM sqlite_master ORDER BY sql;
} {}
# 2022-12-03 Ticket e8b674241947eb3b
# Improve estimates for the cost of sorting relative
# to the cost of doing an index lookup, so as to get
# a better query plan. See the ticket for a deetailed
# example.
#
reset_db
do_execsql_test 18.1 {
CREATE TABLE t1(a INTEGER PRIMARY KEY, b, c);
WITH RECURSIVE c(x) AS (VALUES(1) UNION ALL SELECT x+1 FROM c WHERE x<50)
-- increase to 5000 for actual test data ----^^
INSERT INTO t1(a,b,c) SELECT x, random()%5000, random()%5000 FROM c;
CREATE TABLE t2(d,e,f);
WITH RECURSIVE c(x) AS (VALUES(1) UNION ALL SELECT x+1 FROM c WHERE x<500)
-- increase to 50000 for actual test data -----^^^
INSERT INTO t2(d,e,f) SELECT
NULLIF(0, random()%2), random()%5000, random()%5000
FROM c;
ANALYZE;
UPDATE sqlite_stat1 SET stat='50000' WHERE tbl='t2';
UPDATE sqlite_stat1 SET stat='5000' WHERE tbl='t1';
ANALYZE sqlite_schema;
} {}
do_execsql_test 18.2 {
EXPLAIN QUERY PLAN
SELECT a FROM t1 JOIN t2
WHERE a IN (1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20)
AND a=CASE WHEN d IS NOT NULL THEN e ELSE f END
ORDER BY a;
} {/.*SCAN t2.*SEARCH t1.*/}
# ^^^^^^^--^^^^^^^^^--- t2 should be the outer loop.
finish_test