Slow Performance for some queries
Hi there,
I have discovered some very low performing queries on our MariaDB version 5.3.7. The query shows up with "string results in query cache"
The query:
explain select distinct `config`.`agent_id` AS `agent_id`, `config`.`agent_name` AS `agent_name`, `agent`.`agent_version` AS `agent_version`, `config`.`agent_os` AS `agent_os`, `agent`.`agent_os_version` AS `agent_os_version`, `config`.`pconfig_line` AS `pconfig_line`, `config`.`appclass` AS `appclass`, `config`.`instance` AS `instance`, `config`.`parameter` AS `parameter`, `config`.`value` AS `value`, substring_index(substring_index(`config`.`variable`, '/', '4ö'), '/', -(1)) AS `NT_Drive`, `config`.`agent_config_date` AS `agent_config_date`, `config`.`rule_type_name` AS `rule_type_name` from (`agent_config_detail_view` `config` left join `agent` ON ((`agent`.`agent_id` = `config`.`agent_id`))) where (((`config`.`rule_type_id` = 'ccbe914e30c6ec6e3aa5c4780a3525d6') or (`config`.`rule_type_id` = '0091efee7f9b5f0e27211eb7226d0a23') or (`config`.`rule_type_id` = '6311ae17c1ee52b36e68aaf4ad066387')) and ((`config`.`variable` = '/AgentSetup/FILESYSTEM.filterList') or (`config`.`variable` = '/AgentSetup/FILESYSTEM.filterType') or (`config`.`variable` like '/AS/EVENTSPRING/PARAM_SETTINGS/THRESHOLDS/FILESYSTEM%') or (`config`.`variable` like '/RecoveryActions/NT_LOGICAL_DISKS/%/LDldFreeSpacePercent/Mode')) and (`config`.`agent_config_date` > ((select max(`s`.`agent_config_date`) from `agent_config` `s`) - interval 24 hour))) order by `config`.`agent_name` , `config`.`appclass`
Here is the explain for the query in question:
id select_type table type possible_keys key key_len ref rows Extra 1 PRIMARY a ALL PRIMARY NULL NULL NULL 7083 "Using temporary; Using filesort" 1 PRIMARY agent eq_ref PRIMARY PRIMARY 34 new_budm.a.agent_id 1 1 PRIMARY b ref PRIMARY,fk_agent_config_agent1,IX_agent_config_date fk_agent_config_agent1 34 new_budm.a.agent_id 3 "Using where" 1 PRIMARY c ref agent_config_rule_fk_agent_config_id,agent_config_rule_fk_rule_id agent_config_rule_fk_agent_config_id 34 new_budm.b.agent_config_id 947 1 PRIMARY d eq_ref PRIMARY,IX_rule_variable PRIMARY 34 new_budm.c.fk_rule_id 1 "Using where" 1 PRIMARY e ref fk_rule_rule_type_rule_type1,fk_rule_rule_type_rule fk_rule_rule_type_rule 34 new_budm.c.fk_rule_id 1 "Using where" 1 PRIMARY f eq_ref PRIMARY PRIMARY 34 new_budm.e.fk_rule_type_id 1 2 SUBQUERY NULL NULL NULL NULL NULL NULL NULL "Select tables optimized away"
The query cache (innodb_buffer_pool_size) is set to 8192M.
Other queries are running fine (perfomance can always be better).
Thank you and regards, Patrick
Answer Answered by Sergei Golubchik in this comment.
you didn't provide the definition of the view, so we cannot see the complete query. Show the view definition and the output of EXPLAIN EXTENDED ...; SHOW WARNINGS;
Comments
Comments loading...
Content reproduced on this site is the property of its respective owners,
and this content is not reviewed in advance by MariaDB. The views, information and opinions
expressed by this content do not necessarily represent those of MariaDB or any other party.