MDEV-31380: Assertion `s->table->opt_range_condition_rows <= s->found_records' failed

LooseScan code set opt_range_condition_rows to be the

  MIN(loose_scan_plan->records, table->records)

totally ignoring possible quick range selects.  If there was a quick
select $QUICK on another index with

  $QUICK->records < loose_scan_plan->records

this would create a situation where

   opt_range_condition_rows > $QUICK->records

which causes an assert in 10.6+ and potentially wrong query plan
choice in 10.5.

Fixed by making opt_range_condition_rows to be the minimum #rows
of any quick select.

Approved-by: Monty <monty@mariadb.org>
This commit is contained in:
Sergei Petrunia 2023-06-01 14:06:06 +03:00
parent bb9da13baf
commit a0e7bd735b
3 changed files with 51 additions and 2 deletions

View file

@ -4204,6 +4204,30 @@ a b s1
2 2 t2:t2a-null;min_t3_b:t3b-null
3 3 t2:1;min_t3_b:3
drop table t1,t2,t3;
#
# MDEV-31380: Assertion `s->table->opt_range_condition_rows <= s->found_records' failed
# (assertion in 10.6+, DBL_MAX costs in 10.5)
#
CREATE TABLE t1 (a INT, b INT, PRIMARY KEY(a), KEY(b)) ENGINE=InnoDB;
INSERT INTO t1 SELECT seq, seq FROM seq_1_to_100;
SET
@tmp=@@optimizer_use_condition_selectivity,
optimizer_use_condition_selectivity = 1,
@tmp2=@@optimizer_trace,
optimizer_trace=1;
SELECT DISTINCT * FROM t1 WHERE a IN (1, 2);
a b
1 1
2 2
select
CAST(json_value(json_extract(trace, '$**.chosen_access_method.cost'), '$[0]')
as DOUBLE) < 1.0e100
from information_schema.optimizer_trace;
CAST(json_value(json_extract(trace, '$**.chosen_access_method.cost'), '$[0]')
as DOUBLE) < 1.0e100
1
set optimizer_use_condition_selectivity = @tmp, optimizer_trace=@tmp2;
drop table t1;
#
# End of 10.5 tests
#

View file

@ -6,6 +6,7 @@
--source include/no_valgrind_without_big.inc
--source include/default_optimizer_switch.inc
--source include/have_innodb.inc
--source include/have_sequence.inc
#
# TODO:
# Add queries with:
@ -1858,6 +1859,30 @@ from t1;
drop table t1,t2,t3;
--echo #
--echo # MDEV-31380: Assertion `s->table->opt_range_condition_rows <= s->found_records' failed
--echo # (assertion in 10.6+, DBL_MAX costs in 10.5)
--echo #
CREATE TABLE t1 (a INT, b INT, PRIMARY KEY(a), KEY(b)) ENGINE=InnoDB;
INSERT INTO t1 SELECT seq, seq FROM seq_1_to_100;
SET
@tmp=@@optimizer_use_condition_selectivity,
optimizer_use_condition_selectivity = 1,
@tmp2=@@optimizer_trace,
optimizer_trace=1;
SELECT DISTINCT * FROM t1 WHERE a IN (1, 2);
select
CAST(json_value(json_extract(trace, '$**.chosen_access_method.cost'), '$[0]')
as DOUBLE) < 1.0e100
from information_schema.optimizer_trace;
set optimizer_use_condition_selectivity = @tmp, optimizer_trace=@tmp2;
drop table t1;
--echo #
--echo # End of 10.5 tests
--echo #

View file

@ -3030,8 +3030,8 @@ int SQL_SELECT::test_quick_select(THD *thd, key_map keys_to_use,
restore_nonrange_trees(&param, tree, backup_keys);
if ((group_trp= get_best_group_min_max(&param, tree, read_time)))
{
param.table->opt_range_condition_rows= MY_MIN(group_trp->records,
head->stat_records());
set_if_smaller(param.table->opt_range_condition_rows,
group_trp->records);
Json_writer_object grp_summary(thd, "best_group_range_summary");
if (unlikely(thd->trace_started()))