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MDEV-4029 SELECT on information_schema using a subquery locks up the information_schema table due to incorrect mutexes handling

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Early evaluation of subqueries in the WHERE conditions on I_S.*_STATUS tables,
otherwise the subquery on this same table will try to acquire LOCK_status twice.
This commit is contained in:
Sergei Golubchik
2013-01-21 10:52:39 +01:00
parent 2e11ca36f2
commit 43c6953fa1
3 changed files with 29 additions and 6 deletions
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8
mysql-test/r/information_schema2.result Normal file
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select variable_name from information_schema.session_status where variable_name =
(select variable_name from information_schema.session_status where variable_name = 'uptime');
variable_name
UPTIME
select variable_name from information_schema.session_variables where variable_name =
(select variable_name from information_schema.session_variables where variable_name = 'basedir');
variable_name
BASEDIR

9
mysql-test/t/information_schema2.test Normal file
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#
# MDEV-4029 SELECT on information_schema using a subquery locks up the information_schema table due to incorrect mutexes handling
#
select variable_name from information_schema.session_status where variable_name =
(select variable_name from information_schema.session_status where variable_name = 'uptime');
select variable_name from information_schema.session_variables where variable_name =
(select variable_name from information_schema.session_variables where variable_name = 'basedir');