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MDEV-297: SHOW EXPLAIN: Server gets stuck until timeout occurs while executing SHOW

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INDEX and SHOW EXPLAIN in parallel
- Rework locking code to use the LOCK_thd_data mutex for all synchronization. This also
  fixed MDEV-301.
This commit is contained in:
Sergey Petrunya
2012-06-07 12:19:06 +04:00
parent 9a7b3bf4b7
commit 2c1e737c6c
6 changed files with 119 additions and 78 deletions
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20
mysql-test/r/show_explain.result
View File

@ -596,4 +596,24 @@ count(*)
212
set debug_dbug='';
drop table t1;
#
# MDEV-297: SHOW EXPLAIN: Server gets stuck until timeout occurs while
# executing SHOW INDEX and SHOW EXPLAIN in parallel
#
CREATE TABLE t1(a INT, b INT, c INT, KEY(a), KEY(b), KEY(c));
INSERT INTO t1 (a) VALUES (3),(1),(5),(1);
set @show_explain_probe_select_id=1;
set debug_dbug='d,show_explain_probe_join_exec_start';
SHOW INDEX FROM t1;
show explain for $thr2;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE STATISTICS ALL NULL NULL NULL NULL NULL Skip_open_table; Scanned all databases
Warnings:
Note 1003 SHOW INDEX FROM t1
Table Non_unique Key_name Seq_in_index Column_name Collation Cardinality Sub_part Packed Null Index_type Comment Index_comment
t1 1 a 1 a A NULL NULL NULL YES BTREE
t1 1 b 1 b A NULL NULL NULL YES BTREE
t1 1 c 1 c A NULL NULL NULL YES BTREE
set debug_dbug='';
DROP TABLE t1;
drop table t0;

20
mysql-test/t/show_explain.test
View File

@ -581,6 +581,26 @@ reap;
set debug_dbug='';
drop table t1;
--echo #
--echo # MDEV-297: SHOW EXPLAIN: Server gets stuck until timeout occurs while
--echo # executing SHOW INDEX and SHOW EXPLAIN in parallel
--echo #
CREATE TABLE t1(a INT, b INT, c INT, KEY(a), KEY(b), KEY(c));
INSERT INTO t1 (a) VALUES (3),(1),(5),(1);
set @show_explain_probe_select_id=1;
set debug_dbug='d,show_explain_probe_join_exec_start';
send SHOW INDEX FROM t1;
connection default;
--source include/wait_condition.inc
evalp show explain for $thr2;
connection con1;
reap;
set debug_dbug='';
DROP TABLE t1;
## TODO: Test this: have several SHOW EXPLAIN requests be queued up for a
## thread and served together.