From ad84fb5c3763b3a5c6c2146c8fc824f0d385c77c Mon Sep 17 00:00:00 2001 From: Annamalai Gurusami Date: Tue, 13 Dec 2011 14:26:12 +0530 Subject: [PATCH] Bug #13117023: Innodb increments handler_read_key when it should not 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. --- mysql-test/suite/innodb/r/innodb.result | 5 +++++ mysql-test/suite/innodb/t/innodb.test | 11 +++++++++++ mysql-test/suite/innodb_plugin/r/innodb.result | 11 +++++++++++ mysql-test/suite/innodb_plugin/t/innodb.test | 11 +++++++++++ storage/innobase/handler/ha_innodb.cc | 1 - storage/innodb_plugin/ChangeLog | 6 ++++++ storage/innodb_plugin/handler/ha_innodb.cc | 1 - 7 files changed, 44 insertions(+), 2 deletions(-) diff --git a/mysql-test/suite/innodb/r/innodb.result b/mysql-test/suite/innodb/r/innodb.result index ad140cc59be..fd311de001c 100644 --- a/mysql-test/suite/innodb/r/innodb.result +++ b/mysql-test/suite/innodb/r/innodb.result @@ -2365,3 +2365,8 @@ t1 CREATE TABLE `t1` ( ) ENGINE=InnoDB DEFAULT CHARSET=latin1 drop table t1; set storage_engine=MyISAM; +Variable_name Value +Handler_read_key 0 +f1 +Variable_name Value +Handler_read_key 1 diff --git a/mysql-test/suite/innodb/t/innodb.test b/mysql-test/suite/innodb/t/innodb.test index ef050390b48..f20ea46b200 100644 --- a/mysql-test/suite/innodb/t/innodb.test +++ b/mysql-test/suite/innodb/t/innodb.test @@ -1389,6 +1389,17 @@ eval set storage_engine=$default; -- disable_query_log SET GLOBAL innodb_thread_concurrency = @innodb_thread_concurrency_orig; +# +# Test fix for bug 13117023. InnoDB increments HA_READ_KEY_COUNT (aka +# HANDLER_READ_KEY) when it should not. +# +create table t1 (f1 integer primary key) engine=innodb; +flush status; +show status like "handler_read_key"; +select f1 from t1; +show status like "handler_read_key"; +drop table t1; + ####################################################################### # # # Please, DO NOT TOUCH this file as well as the innodb.result file. # diff --git a/mysql-test/suite/innodb_plugin/r/innodb.result b/mysql-test/suite/innodb_plugin/r/innodb.result index cdb61f3ba98..9435670f42d 100644 --- a/mysql-test/suite/innodb_plugin/r/innodb.result +++ b/mysql-test/suite/innodb_plugin/r/innodb.result @@ -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; diff --git a/mysql-test/suite/innodb_plugin/t/innodb.test b/mysql-test/suite/innodb_plugin/t/innodb.test index 1480492cf2a..d4f2088cc50 100644 --- a/mysql-test/suite/innodb_plugin/t/innodb.test +++ b/mysql-test/suite/innodb_plugin/t/innodb.test @@ -2571,6 +2571,17 @@ SET GLOBAL innodb_thread_concurrency = @innodb_thread_concurrency_orig; # Clean up after the Bug#55284/Bug#58912 test case. DROP TABLE bug58912; +# +# Test fix for bug 13117023. InnoDB increments HA_READ_KEY_COUNT (aka +# HANDLER_READ_KEY) when it should not. +# +create table t1 (f1 integer primary key) engine=innodb; +flush status; +show status like "handler_read_key"; +select f1 from t1; +show status like "handler_read_key"; +drop table t1; + ####################################################################### # # # Please, DO NOT TOUCH this file as well as the innodb.result file. # diff --git a/storage/innobase/handler/ha_innodb.cc b/storage/innobase/handler/ha_innodb.cc index 6709f790994..a4d79a5934e 100644 --- a/storage/innobase/handler/ha_innodb.cc +++ b/storage/innobase/handler/ha_innodb.cc @@ -4802,7 +4802,6 @@ ha_innobase::innobase_get_index( dict_index_t* index = 0; DBUG_ENTER("innobase_get_index"); - ha_statistic_increment(&SSV::ha_read_key_count); ut_ad(user_thd == ha_thd()); ut_a(prebuilt->trx == thd_to_trx(user_thd)); diff --git a/storage/innodb_plugin/ChangeLog b/storage/innodb_plugin/ChangeLog index 37668b43697..5fc0cce3ff2 100644 --- a/storage/innodb_plugin/ChangeLog +++ b/storage/innodb_plugin/ChangeLog @@ -1,3 +1,9 @@ +2011-12-13 The InnoDB Team + + * handler/ha_innodb.cc, innodb.test, innodb.result: + Fix Bug#13117023: InnoDB was incrementing the handler_read_key, + also the SSV::ha_read_key_count, at the wrong place. + 2011-12-10 The InnoDB Team * include/page0page.h, page/page0page.c: diff --git a/storage/innodb_plugin/handler/ha_innodb.cc b/storage/innodb_plugin/handler/ha_innodb.cc index d84bd38ba7e..122bf1f7846 100644 --- a/storage/innodb_plugin/handler/ha_innodb.cc +++ b/storage/innodb_plugin/handler/ha_innodb.cc @@ -5520,7 +5520,6 @@ ha_innobase::innobase_get_index( dict_index_t* index = 0; DBUG_ENTER("innobase_get_index"); - ha_statistic_increment(&SSV::ha_read_key_count); if (keynr != MAX_KEY && table->s->keys > 0) { key = table->key_info + keynr;