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author | Varun Gupta <varun.gupta@mariadb.com> | 2019-08-26 20:59:51 +0530 |
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committer | Varun Gupta <varun.gupta@mariadb.com> | 2019-08-27 08:21:55 +0530 |
commit | 77e44282ff8628975298f74796d19f0307f34dc8 (patch) | |
tree | 16efe019a60e936b375ae5d7d68c7e13f737cc19 | |
parent | 6afe013cde26ac9a038b705ac676d1c49d4280a1 (diff) | |
download | mariadb-git-77e44282ff8628975298f74796d19f0307f34dc8.tar.gz |
MDEV-19705: Assertion `tmp >= 0' failed in best_access_path
The reason for hitting the assert is that rec_per_key estimates have some garbage value.
So the solution to fix this would be for long unique keys to use use rec_per_key for only 1 keypart,
that means rec_per_key[0] would have the estimate.
-rw-r--r-- | mysql-test/main/long_unique.result | 15 | ||||
-rw-r--r-- | mysql-test/main/long_unique.test | 14 | ||||
-rw-r--r-- | sql/table.cc | 4 |
3 files changed, 32 insertions, 1 deletions
diff --git a/mysql-test/main/long_unique.result b/mysql-test/main/long_unique.result index 8ea6d36c321..a4955b3e7b5 100644 --- a/mysql-test/main/long_unique.result +++ b/mysql-test/main/long_unique.result @@ -1462,4 +1462,19 @@ t1 CREATE TABLE `t1` ( KEY `pk` (`pk`,`a`) ) ENGINE=MyISAM DEFAULT CHARSET=latin1 drop table t1; +# +# MDEV-19705: Assertion `tmp >= 0' failed in best_access_path +# +CREATE TABLE t1 (d varchar(10)) ENGINE=MyISAM; +INSERT INTO t1 VALUES ('a'),('q'); +CREATE TABLE t2 (f varchar(10), a2 datetime, b int, a1 varchar(1024), pk int NOT NULL, PRIMARY KEY (pk), UNIQUE KEY (f,a1,a2), KEY f2 (f(4),a2)) ENGINE=MyISAM; +INSERT INTO t2 VALUES ('aaa','1985-09-06',-163,'s',1),('bbb','1995-01-05',3,'pucaz',2),('ccc','0000-00-00',NULL,'help',3),('ddd',NULL,618,'v',4),('eee','1995-12-20',410,'m',5),('ffq','1976-06-12 20:02:56',NULL,'POKNC',6),('dddd','0000-00-00',-328,'hgsu',7); +explain +SELECT t2.b FROM t1 JOIN t2 ON t1.d = t2.f WHERE t2.pk >= 20; +id select_type table type possible_keys key key_len ref rows Extra +1 SIMPLE t2 range PRIMARY,f,f2 PRIMARY 4 NULL 1 Using index condition +1 SIMPLE t1 ALL NULL NULL NULL NULL 2 Using where; Using join buffer (flat, BNL join) +SELECT t2.b FROM t1 JOIN t2 ON t1.d = t2.f WHERE t2.pk >= 20; +b +drop table t1,t2; set @@GLOBAL.max_allowed_packet= @allowed_packet; diff --git a/mysql-test/main/long_unique.test b/mysql-test/main/long_unique.test index a6bc68f54dc..c0bd77ca5c9 100644 --- a/mysql-test/main/long_unique.test +++ b/mysql-test/main/long_unique.test @@ -542,4 +542,18 @@ alter table t1 modify a varchar(1000); show create table t1; drop table t1; +--echo # +--echo # MDEV-19705: Assertion `tmp >= 0' failed in best_access_path +--echo # + +CREATE TABLE t1 (d varchar(10)) ENGINE=MyISAM; +INSERT INTO t1 VALUES ('a'),('q'); + +CREATE TABLE t2 (f varchar(10), a2 datetime, b int, a1 varchar(1024), pk int NOT NULL, PRIMARY KEY (pk), UNIQUE KEY (f,a1,a2), KEY f2 (f(4),a2)) ENGINE=MyISAM; +INSERT INTO t2 VALUES ('aaa','1985-09-06',-163,'s',1),('bbb','1995-01-05',3,'pucaz',2),('ccc','0000-00-00',NULL,'help',3),('ddd',NULL,618,'v',4),('eee','1995-12-20',410,'m',5),('ffq','1976-06-12 20:02:56',NULL,'POKNC',6),('dddd','0000-00-00',-328,'hgsu',7); +explain +SELECT t2.b FROM t1 JOIN t2 ON t1.d = t2.f WHERE t2.pk >= 20; +SELECT t2.b FROM t1 JOIN t2 ON t1.d = t2.f WHERE t2.pk >= 20; +drop table t1,t2; + set @@GLOBAL.max_allowed_packet= @allowed_packet; diff --git a/sql/table.cc b/sql/table.cc index 1ab4df0f7cf..da0c4be41b0 100644 --- a/sql/table.cc +++ b/sql/table.cc @@ -800,7 +800,8 @@ static bool create_key_infos(const uchar *strpos, const uchar *frm_image_end, { if (strpos + (new_frm_ver >= 1 ? 9 : 7) >= frm_image_end) return 1; - *rec_per_key++=0; + if (!(keyinfo->algorithm == HA_KEY_ALG_LONG_HASH)) + *rec_per_key++=0; key_part->fieldnr= (uint16) (uint2korr(strpos) & FIELD_NR_MASK); key_part->offset= (uint) uint2korr(strpos+2)-1; key_part->key_type= (uint) uint2korr(strpos+5); @@ -828,6 +829,7 @@ static bool create_key_infos(const uchar *strpos, const uchar *frm_image_end, { keyinfo->key_length= HA_HASH_KEY_LENGTH_WITHOUT_NULL; key_part++; // reserved for the hash value + *rec_per_key++=0; } /* |