mariadb/mysql-test/r/error_simulation.result
Sergey Glukhov 14dc91ff83 Bug#11747970 34660: CRASH WHEN FEDERATED TABLE LOSES CONNECTION DURING INSERT ... SELECT
Problematic query:
insert ignore into `t1_federated` (`c1`) select `c1` from  `t1_local` a
where not exists (select 1 from `t1_federated` b where a.c1 = b.c1);
When this query is killed in another connection it could lead to crash.
The problem is follwing:
An attempt to obtain table statistics for subselect table in killed query
fails with an error. So JOIN::optimize() for subquery is failed but
it does not prevent further subquery evaluation.
At the first subquery execution JOIN::optimize() is called
(see subselect_single_select_engine::exec()) and fails with
an error. 'executed' flag is set to TRUE and it prevents
further subquery evaluation. At the second call
JOIN::optimize() does not happen as 'JOIN::optimized' is TRUE
and in case of uncacheable subquery the 'executed' flag is set
to FALSE before subquery evaluation. So we loose 'optimize stage'
error indication (see subselect_single_select_engine::exec()).
In other words 'executed' flag is used for two purposes, for
error indication at JOIN::optimize() stage and for an
indication of subquery execution. And it seems it's wrong
as the flag could be reset.


mysql-test/r/error_simulation.result:
  test case
mysql-test/t/error_simulation.test:
  test case
sql/item_subselect.cc:
  added new flag subselect_single_select_engine::optimize_error
  which is used for error detection which could happen at optimize
  stage.
sql/item_subselect.h:
  added new flag subselect_single_select_engine::optimize_error
sql/sql_select.cc:
  test case
2011-10-05 13:28:20 +04:00

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Text

DROP TABLE IF EXISTS t1;
Warnings:
Note 1051 Unknown table 't1'
CREATE TABLE t1 (
a varchar(32) character set utf8 collate utf8_bin NOT NULL,
b varchar(32) character set utf8 collate utf8_bin NOT NULL )
ENGINE=MyISAM DEFAULT CHARSET=utf8;
INSERT INTO t1 VALUES
('AAAAAAAAAA','AAAAAAAAAA'), ('AAAAAAAAAB','AAAAAAAAAB '),
('AAAAAAAAAB','AAAAAAAAAB'), ('AAAAAAAAAC','AAAAAAAAAC'),
('AAAAAAAAAD','AAAAAAAAAD'), ('AAAAAAAAAE','AAAAAAAAAE'),
('AAAAAAAAAF','AAAAAAAAAF'), ('AAAAAAAAAG','AAAAAAAAAG'),
('AAAAAAAAAH','AAAAAAAAAH'), ('AAAAAAAAAI','AAAAAAAAAI'),
('AAAAAAAAAJ','AAAAAAAAAJ'), ('AAAAAAAAAK','AAAAAAAAAK');
set tmp_table_size=1024;
set session debug="d,raise_error";
SELECT MAX(a) FROM t1 GROUP BY a,b;
ERROR 23000: Can't write; duplicate key in table 'tmp_table'
set tmp_table_size=default;
DROP TABLE t1;
#
# Bug #50946: fast index creation still seems to copy the table
#
CREATE TABLE t1 (a INT(100) NOT NULL);
INSERT INTO t1 VALUES (1), (0), (2);
SET SESSION debug='+d,alter_table_only_index_change';
ALTER TABLE t1 ADD INDEX a(a);
SET SESSION debug=DEFAULT;
SHOW CREATE TABLE t1;
Table Create Table
t1 CREATE TABLE `t1` (
`a` int(100) NOT NULL,
KEY `a` (`a`)
) ENGINE=MyISAM DEFAULT CHARSET=latin1
SELECT * FROM t1;
a
0
1
2
DROP TABLE t1;
#
# Bug#42064: low memory crash when importing hex strings, in Item_hex_string::Item_hex_string
#
CREATE TABLE t1(a BLOB);
SET SESSION debug="+d,bug42064_simulate_oom";
INSERT INTO t1 VALUES("");
Got one of the listed errors
SET SESSION debug=DEFAULT;
DROP TABLE t1;
#
# Bug#41660: Sort-index_merge for non-first join table may require
# O(#scans) memory
#
CREATE TABLE t1 (a INT);
INSERT INTO t1 VALUES (0), (1), (2), (3), (4), (5), (6), (7), (8), (9);
CREATE TABLE t2 (a INT, b INT, filler CHAR(100), KEY(a), KEY(b));
INSERT INTO t2 SELECT 1000, 1000, 'filler' FROM t1 A, t1 B, t1 C;
INSERT INTO t2 VALUES (1, 1, 'data');
# the example query uses LEFT JOIN only for the sake of being able to
# demonstrate the issue with a very small dataset. (left outer join
# disables the use of join buffering, so we get the second table
# re-scanned for every record in the outer table. if we used inner join,
# we would need to have thousands of records and/or more columns in both
# tables so that the join buffer is filled and re-scans are triggered).
SET SESSION debug = '+d,only_one_Unique_may_be_created';
EXPLAIN
SELECT * FROM t1 LEFT JOIN t2 ON ( t2.a < 10 OR t2.b < 10 );
id select_type table type possible_keys key key_len ref rows Extra
x x x x x x x x x
x x x x x x x x x Using sort_union(a,b); Using where
SELECT * FROM t1 LEFT JOIN t2 ON ( t2.a < 10 OR t2.b < 10 );
a a b filler
0 1 1 data
1 1 1 data
2 1 1 data
3 1 1 data
4 1 1 data
5 1 1 data
6 1 1 data
7 1 1 data
8 1 1 data
9 1 1 data
SET SESSION debug = DEFAULT;
DROP TABLE t1, t2;
#
# Bug#11747970 34660: CRASH WHEN FEDERATED TABLE LOSES CONNECTION DURING INSERT ... SELECT
#
CREATE TABLE t1(f1 INT, KEY(f1));
CREATE TABLE t2(f1 INT);
INSERT INTO t1 VALUES (1),(2);
INSERT INTO t2 VALUES (1),(2);
SET SESSION debug='d,bug11747970_simulate_error';
INSERT IGNORE INTO t2 SELECT f1 FROM t1 a WHERE NOT EXISTS (SELECT 1 FROM t2 b WHERE a.f1 = b.f1);
Warnings:
Error 1105 Unknown error
SET SESSION debug = DEFAULT;
DROP TABLE t1,t2;
#
# End of 5.1 tests
#