From 4addd31531f722438b8b702c9cd00c28b61efce3 Mon Sep 17 00:00:00 2001 From: Sergei Petrunia Date: Fri, 11 Dec 2020 18:54:21 +0300 Subject: MDEV-21958: Query having many NOT-IN clauses running forever Basic variant of the fix: do not consider conditions in form unique_key NOT IN (c1,c2...) to be sargable. If there are only a few constants, the condition is not selective. If there are a lot constants, the overhead of processing such a huge range list is not worth it. --- mysql-test/main/range_mrr_icp.result | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+) (limited to 'mysql-test/main/range_mrr_icp.result') diff --git a/mysql-test/main/range_mrr_icp.result b/mysql-test/main/range_mrr_icp.result index 826ac621064..ebefc21a58d 100644 --- a/mysql-test/main/range_mrr_icp.result +++ b/mysql-test/main/range_mrr_icp.result @@ -3238,6 +3238,36 @@ analyze SELECT * FROM t1 where a in (0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17 id select_type table type possible_keys key key_len ref rows r_rows filtered r_filtered Extra 1 SIMPLE t1 index a a 5 NULL 2000 2000.00 10.05 60.05 Using where; Using index drop table t1,ten,t2; +# +# MDEV-21958: Query having many NOT-IN clauses running forever +# +create table t2 ( +pk int primary key, +key1 int, +col1 int, +key (key1, pk) +); +insert into t2 (pk, key1) values (1,1),(2,2),(3,3),(4,4),(5,5); +set @tmp_21958=@@optimizer_trace; +set optimizer_trace=1; +explain select * from t2 where key1 in (1,2,3) and pk not in (1,2,3); +id select_type table type possible_keys key key_len ref rows Extra +1 SIMPLE t2 ALL PRIMARY,key1 NULL NULL NULL 5 Using where +# This should show only ranges in form "(1) <= (key1) <= (1)" +# ranges over "pk" should not be constructed. +select json_detailed(JSON_EXTRACT(trace, '$**.ranges')) +from information_schema.optimizer_trace; +json_detailed(JSON_EXTRACT(trace, '$**.ranges')) +[ + + [ + "(1) <= (key1) <= (1)", + "(2) <= (key1) <= (2)", + "(3) <= (key1) <= (3)" + ] +] +set optimizer_trace=@tmp_21958; +drop table t2; # End of 10.4 tests set global innodb_stats_persistent= @innodb_stats_persistent_save; set global innodb_stats_persistent_sample_pages= -- cgit v1.2.1