revision-id: 5101514e2697625c90ba053b8ae9635a32c86177 (mariadb-10.6.1-270-g5101514e269) parent(s): 49b38c82a8d6b1e745704938bdf5fda82bbb0916 author: Sergei Petrunia committer: Sergei Petrunia timestamp: 2022-01-10 16:19:03 +0300 message: MDEV-27426: Wrong result upon query using index_merge with DESC key Make QUICK_RANGE_SELECT::cmp_next() aware of reverse-ordered key parts. (QUICK_RANGE_SELECT::cmp_prev() uses key_cmp() and so it already works correctly) --- mysql-test/main/desc_index_range.result | 10 ++++++++++ mysql-test/main/desc_index_range.test | 10 ++++++++++ sql/opt_range.cc | 9 +++++---- 3 files changed, 25 insertions(+), 4 deletions(-) diff --git a/mysql-test/main/desc_index_range.result b/mysql-test/main/desc_index_range.result index 244659e3f48..edf13010829 100644 --- a/mysql-test/main/desc_index_range.result +++ b/mysql-test/main/desc_index_range.result @@ -179,3 +179,13 @@ json_detailed(json_extract(trace, '$**.potential_group_range_indexes')) ] drop table t1; set optimizer_trace=default; +# +# MDEV-27426: Wrong result upon query using index_merge with DESC key +# +CREATE OR REPLACE TABLE t1 (pk INT, a INT, b int, KEY(a), PRIMARY KEY(pk DESC)) ENGINE=InnoDB; +INSERT INTO t1 VALUES (1,4,5),(2,9,6),(3,NULL,7),(4,NULL,8); +SELECT * FROM t1 WHERE pk > 10 OR a > 0; +pk a b +1 4 5 +2 9 6 +DROP TABLE t1; diff --git a/mysql-test/main/desc_index_range.test b/mysql-test/main/desc_index_range.test index bcb9ce83318..2f3d36c8305 100644 --- a/mysql-test/main/desc_index_range.test +++ b/mysql-test/main/desc_index_range.test @@ -86,3 +86,13 @@ from information_schema.optimizer_trace; drop table t1; set optimizer_trace=default; + +--echo # +--echo # MDEV-27426: Wrong result upon query using index_merge with DESC key +--echo # + +CREATE OR REPLACE TABLE t1 (pk INT, a INT, b int, KEY(a), PRIMARY KEY(pk DESC)) ENGINE=InnoDB; +INSERT INTO t1 VALUES (1,4,5),(2,9,6),(3,NULL,7),(4,NULL,8); + +SELECT * FROM t1 WHERE pk > 10 OR a > 0; +DROP TABLE t1; diff --git a/sql/opt_range.cc b/sql/opt_range.cc index 7b70dca86a6..ab734c6ed11 100644 --- a/sql/opt_range.cc +++ b/sql/opt_range.cc @@ -13076,24 +13076,25 @@ int QUICK_RANGE_SELECT::cmp_next(QUICK_RANGE *range_arg) key+= store_length, key_part++) { int cmp; + bool reverse= MY_TEST(key_part->flag & HA_REVERSE_SORT); store_length= key_part->store_length; if (key_part->null_bit) { if (*key) { if (!key_part->field->is_null()) - return 1; + return reverse ? 0 : 1; continue; } else if (key_part->field->is_null()) - return 0; + return reverse ? 1 : 0; key++; // Skip null byte store_length--; } if ((cmp=key_part->field->key_cmp(key, key_part->length)) < 0) - return 0; + return reverse ? 1 : 0; if (cmp > 0) - return 1; + return reverse ? 0 : 1; } return (range_arg->flag & NEAR_MAX) ? 1 : 0; // Exact match }