mariadb/mysql-test/suite/innodb/r/innodb_bug14704286.result
Krunal Bauskar krunal.bauskar@oracle.com 9bfc910f2f bug#14704286
SECONDARY INDEX UPDATES MAKE CONSISTENT READS DO O(N^2) UNDO PAGE
LOOKUPS (honoring kill query while accessing sec_index)

If secondary index is being used for select query evaluation and this
query is operating with consistent read snapshot it might take good time for
secondary index to return back control to mysql as MVCC would kick in.

If user issues "kill query <id>" while query is actively accessing
secondary index it will not be honored as there is no hook to check
for this condition. Added hook for this check.

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Parallely secondary index taking too long to evaluate for consistent
read snapshot case is being examined for performance improvement. WL#6540.
2012-10-15 09:24:33 +05:30

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use test;
drop table if exists t1;
Warnings:
Note 1051 Unknown table 't1'
create table t1 (id int primary key, value int, value2 int,
value3 int, index(value,value2)) engine=innodb;
insert into t1 values
(10,10,10,10),(11,11,11,11),(12,12,12,12),(13,13,13,13),(14,14,14,14),
(15,15,15,15),(16,16,16,16),(17,17,17,17),(18,18,18,18),(19,19,19,19),
(20,20,20,20);
use test;
start transaction with consistent snapshot;
use test;
CREATE PROCEDURE update_t1()
BEGIN
DECLARE i INT DEFAULT 1;
while (i <= 5000) DO
update test.t1 set value2=value2+1, value3=value3+1 where id=12;
SET i = i + 1;
END WHILE;
END|
CALL update_t1();
select * from t1;
id value value2 value3
10 10 10 10
11 11 11 11
12 12 5012 5012
13 13 13 13
14 14 14 14
15 15 15 15
16 16 16 16
17 17 17 17
18 18 18 18
19 19 19 19
20 20 20 20
select * from t1 force index(value) where value=12;
kill query @id;
ERROR 70100: Query execution was interrupted
select * from t1 where value = 12;
id value value2 value3
12 12 12 12
drop procedure if exists update_t1;
drop table if exists t1;