[MDEV-31258] Assertion `cond_selectivity <= 1.000000001' upon range query (actual value 1.33) Created: 2023-05-12  Updated: 2023-05-27  Resolved: 2023-05-27

Status: Closed
Project: MariaDB Server
Component/s: Optimizer
Affects Version/s: 11.0
Fix Version/s: 11.0.2

Type: Bug Priority: Critical
Reporter: Elena Stepanova Assignee: Michael Widenius
Resolution: Fixed Votes: 0
Labels: None

Issue Links:
Problem/Incident
is caused by MDEV-26974 Improve selectivity and related costs... Closed

 Description    

--source include/have_innodb.inc
 
 
 
CREATE TABLE t (id int, a int, b char(3), PRIMARY KEY (id), KEY idx (a,b)) ENGINE=InnoDB;
 
 
 
INSERT INTO t VALUES
 
(1,8,'UT'),(2,0,'NU'),(3,1,'SD'),(4,0,'QU'),(5,0,'FL'),(6,0,'ZR'),
 
(7,3,'LA'),(8,5,'NU'),(9,0,'NU'),(10,0,'SD'),(11,0,'NU'),(12,1,'SD'),
 
(13,0,'BD'),(14,0,'PA'),(15,0,'VT'),(16,4,'WA'),(17,0,'ME'),(18,6,'OH'),
 
(19,0,'ME'),(20,4,'NU'),(21,0,'SC'),(22,0,'GA'),(23,1,'CO'),(24,0,'IL'),
 
(25,0,'GA'),(26,0,'HI'),(27,0,'BU'),(28,0,'NU'),(29,7,'LA'),(30,0,'NU'),
 
(31,0,'JR'),(32,6,'BR'),(33,0,'NU'),(34,6,'CO'),(35,7,'NU'),(36,2,'LA'),
 
(37,0,'PR'),(38,1,'UT'),(39,2,'BR'),(40,1,'HI'),(41,0,'SD'),(42,0,'RI'),
 
(43,2,'LA'),(44,0,'TN'),(45,4,'HI'),(46,0,'VT'),(47,1,'NU'),(48,0,'SC'),
 
(49,0,'TX'),(50,8,'DC'),(51,4,'NU'),(52,0,'AL'),(53,0,'CO'),(54,9,'PR'),
 
(55,0,'AR'),(56,0,'SD'),(57,0,'RI'),(58,0,'XE'),(59,0,'NU'),(60,4,'EL'),
 
(61,2,'LA'),(62,5,'UT'),(63,3,'NU'),(64,0,'RI'),(65,1,'NU'),(66,0,'BR'),
 
(67,3,'WA'),(68,0,'TN'),(69,3,'HI'),(70,0,'OH'),(71,8,'GA'),(72,6,'AL'),
 
(73,6,'NU'),(74,1,'HI'),(75,5,'JR'),(76,3,'RI'),(77,0,'DC'),(78,0,'SC'),
 
(79,0,'CO'),(80,2,'BO'),(81,8,'XE'),(82,1,'NU'),(83,0,'SD'),(84,0,'PA'),
 
(85,5,'PA'),(86,0,'QU'),(87,0,'PA'),(88,0,'NU'),(89,0,'ND'),(90,0,'UT'),
 
(91,0,'NU'),(92,0,'NU'),(93,6,'ZR'),(94,0,'NU'),(95,2,'EL'),(96,0,'NU'),
 
(97,0,'RI'),(98,5,'DC'),(99,7,'JR'),(100,5,'CO'),(101,0,'UT'),(102,0,'QU'),
 
(103,0,'NU'),(104,0,'GA'),(105,7,'AK'),(106,0,'ZR'),(107,0,'YT'),(108,0,'MD'),
 
(109,0,'NU'),(110,1,'EL'),(111,0,'ME'),(112,0,'VT'),(113,2,'NU'),(114,0,'CO'),
 
(115,5,'TN'),(116,0,'OH'),(117,0,'GA'),(118,9,'GA'),(119,0,'CO'),(120,0,'AL'),
 
(121,0,'NU'),(122,2,'NE'),(123,2,'TX'),(124,3,'CO'),(125,0,'TN'),(126,0,'WA'),
 
(127,0,'NE'),(128,6,'TN'),(129,0,'BR'),(130,0,'ID'),(131,0,'NU'),(132,2,'EL'),
 
(133,0,'PR'),(134,0,'NU'),(135,1,'AZ'),(136,7,'EL'),(137,0,'TN'),(138,0,'PA'),
 
(139,5,'QU'),(140,0,'AR'),(141,0,'DC'),(142,2,'WA'),(143,7,'OH'),(144,2,'CO'),
 
(145,6,'NU'),(146,9,'FL'),(147,0,'HI'),(148,0,'WA'),(149,1,'BR'),(150,3,'QU');
 
 
 
ANALYZE TABLE t PERSISTENT FOR ALL; # Optional, fails either way
 
 
 
SELECT id, MIN(id) FROM t
 
WHERE (b > 'TX' OR b BETWEEN 'NE' AND 'SC') AND id IN (1,7,8) AND a = 5
 
GROUP BY id;

11.0 368dd22a

 
mariadbd: /data/src/11.0/sql/sql_select.cc:31338: bool get_range_limit_read_cost(const POSITION*, const TABLE*, uint, ha_rows, ha_rows, double*, double*): Assertion `cond_selectivity <= 1.000000001' failed.
 
230512 22:04:12 [ERROR] mysqld got signal 6 ;
 
 
 
#9  0x00007fbe85453df2 in __GI___assert_fail (assertion=0x5558d62daa60 "cond_selectivity <= 1.000000001", file=0x5558d62c8ae0 "/data/src/11.0/sql/sql_select.cc", line=31338, function=0x5558d62daaa0 "bool get_range_limit_read_cost(const POSITION*, const TABLE*, uint, ha_rows, ha_rows, double*, double*)") at ./assert/assert.c:101
 
#10 0x00005558d43ee056 in get_range_limit_read_cost (pos=0x629000349080, table=0x6190000f7398, keynr=0, rows_limit_arg=150, rows_to_scan=150, read_cost=0x7fbe710a9ba0, read_rows=0x7fbe710a9bc0) at /data/src/11.0/sql/sql_select.cc:31338
 
#11 0x00005558d43eff8c in test_if_cheaper_ordering (tab=0x629000349fb0, order=0x6290000fc8a0, table=0x6190000f7398, usable_keys=..., ref_key=1, select_limit_arg=150, new_key=0x7fbe710a9ea0, new_key_direction=0x7fbe710a9ed0, new_select_limit=0x7fbe710a9f60, new_used_key_parts=0x7fbe710a9eb0, saved_best_key_parts=0x7fbe710a9ec0) at /data/src/11.0/sql/sql_select.cc:31698
 
#12 0x00005558d43c7522 in test_if_skip_sort_order (tab=0x629000349fb0, order=0x6290000fc8a0, select_limit=18446744073709551615, no_changes=false, map=0x6190000f7428) at /data/src/11.0/sql/sql_select.cc:26252
 
#13 0x00005558d431e286 in JOIN::optimize_stage2 (this=0x6290000fd2f0) at /data/src/11.0/sql/sql_select.cc:3287
 
#14 0x00005558d43170f3 in JOIN::optimize_inner (this=0x6290000fd2f0) at /data/src/11.0/sql/sql_select.cc:2603
 
#15 0x00005558d430fe47 in JOIN::optimize (this=0x6290000fd2f0) at /data/src/11.0/sql/sql_select.cc:1905
 
#16 0x00005558d4331ab3 in mysql_select (thd=0x62b00017a218, tables=0x6290000faca8, fields=..., conds=0x6290000fc210, og_num=1, order=0x0, group=0x6290000fc8a0, having=0x0, proc_param=0x0, select_options=2164525824, result=0x6290000fd2c0, unit=0x62b00017e660, select_lex=0x6290000fa380) at /data/src/11.0/sql/sql_select.cc:5144
 
#17 0x00005558d43016e8 in handle_select (thd=0x62b00017a218, lex=0x62b00017e588, result=0x6290000fd2c0, setup_tables_done_option=0) at /data/src/11.0/sql/sql_select.cc:616
 
#18 0x00005558d4226ac4 in execute_sqlcom_select (thd=0x62b00017a218, all_tables=0x6290000faca8) at /data/src/11.0/sql/sql_parse.cc:6279
 
#19 0x00005558d4214eeb in mysql_execute_command (thd=0x62b00017a218, is_called_from_prepared_stmt=false) at /data/src/11.0/sql/sql_parse.cc:3949
 
#20 0x00005558d4231574 in mysql_parse (thd=0x62b00017a218, rawbuf=0x6290000fa238 "SELECT id, MIN(id) FROM t\nWHERE (b > 'TX' OR b BETWEEN 'NE' AND 'SC') AND id IN (1,7,8) AND a = 5\nGROUP BY id", length=109, parser_state=0x7fbe710aba20) at /data/src/11.0/sql/sql_parse.cc:8014
 
#21 0x00005558d4207460 in dispatch_command (command=COM_QUERY, thd=0x62b00017a218, packet=0x629000285219 "SELECT id, MIN(id) FROM t\nWHERE (b > 'TX' OR b BETWEEN 'NE' AND 'SC') AND id IN (1,7,8) AND a = 5\nGROUP BY id", packet_length=109, blocking=true) at /data/src/11.0/sql/sql_parse.cc:1894
 
#22 0x00005558d4204183 in do_command (thd=0x62b00017a218, blocking=true) at /data/src/11.0/sql/sql_parse.cc:1407
 
#23 0x00005558d46cc00c in do_handle_one_connection (connect=0x608000003938, put_in_cache=true) at /data/src/11.0/sql/sql_connect.cc:1416
 
#24 0x00005558d46cb9cd in handle_one_connection (arg=0x6080000038b8) at /data/src/11.0/sql/sql_connect.cc:1318
 
#25 0x00005558d52c0324 in pfs_spawn_thread (arg=0x617000008218) at /data/src/11.0/storage/perfschema/pfs.cc:2201
 
#26 0x00007fbe854a7fd4 in start_thread (arg=<optimized out>) at ./nptl/pthread_create.c:442
 
#27 0x00007fbe855285bc in clone3 () at ../sysdeps/unix/sysv/linux/x86_64/clone3.S:81


(gdb) f 10
 
#10 0x0000556827d5a056 in get_range_limit_read_cost (pos=0x629000349080, table=0x6190000f7398, keynr=0, rows_limit_arg=150, 
    rows_to_scan=150, read_cost=0x7f6fffc6dba0, read_rows=0x7f6fffc6dbc0) at /data/src/11.0/sql/sql_select.cc:31338
 
31338	      DBUG_ASSERT(cond_selectivity <= 1.000000001);
 
(gdb) p cond_selectivity
 
$1 = 1.3333333333333333



 Comments   
Comment by Michael Widenius [ 2023-05-27 ]

This was caused of two minor issues:

  • get_quick_record_count() returned the number of rows for range with
    least cost, when it should have returned the minum number of rows
    for any range.
  • When changing REF to RANGE, we also changed records_out, which
    should not be done (number of records in the result will not
    change).
Comment by Michael Widenius [ 2023-05-27 ]

Pushed to 11.0

Generated at Thu Feb 08 10:22:29 UTC 2024 using Jira 8.20.16#820016-sha1:9d11dbea5f4be3d4cc21f03a88dd11d8c8687422.