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Bug #13117023: Innodb increments handler_read_key when it should not

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The counter handler_read_key (SSV::ha_read_key_count) is incremented 
incorrectly.

The mysql server maintains a per thread system_status_var (SSV)
object.  This object contains among other things the counter
SSV::ha_read_key_count. The purpose of this counter is to measure the
number of requests to read a row based on a key (or the number of
index lookups).

This counter was wrongly incremented in the
ha_innobase::innobase_get_index(). The fix removes
this increment statement (for both innodb and innodb_plugin).

The various callers of the innobase_get_index() was checked to
determine if anybody must increment this counter (if they first call
innobase_get_index() and then perform an index lookup).  It was found
that no caller of innobase_get_index() needs to worry about the
SSV::ha_read_key_count counter.
This commit is contained in:
Annamalai Gurusami
2011-12-13 14:26:12 +05:30
parent 3d58fd6900
commit ad84fb5c37
7 changed files with 44 additions and 2 deletions
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11
mysql-test/suite/innodb_plugin/r/innodb.result
View File

@@ -3257,3 +3257,14 @@ Handler_update 1
Variable_name Value
Handler_delete 1
DROP TABLE bug58912;
create table t1 (f1 integer primary key) engine=innodb;
flush status;
show status like "handler_read_key";
Variable_name Value
Handler_read_key 0
select f1 from t1;
f1
show status like "handler_read_key";
Variable_name Value
Handler_read_key 1
drop table t1;