Greetings,
I am seeing excessive size of MySQL tmp files when executing queries against an InnoDB format database. Otherwise, no apparent errors or concerns.
With one query I compared our server and a peer's server:
Our Server:
Query generated a 2GB tmp file
Primary table of query focus had 100,000 records in it
Total database size is just under 200MB
Took 41 seconds to complete
Peer's Server:
Query generated a 50MB tmp file
Primary table of query focus had 200,000 records in it
Total database size is around 6GB
Tool 20 seconds to complete
My main objection is to the excessive size of tmp files created when the query is executing.
Is there some type of health check up utilities for InnoDB database support / care & feeding?
Second query compared between current production server and new production server exports a list of contacts - approximately 2400 records in total. That query will not complete on the current production server, ending in a generic Apache timeout message - not even a web application customized error message. On the new server the query does complete after a long LONG time, and again 2GB file was generated while the query was processing.
Current production server has the following software versions:
OS: CentOS release 5.9 (Final)
MySQL: 5.0.95
New server:
OS: Ubuntu 12.04
MySQL: 5.5.37
As a way of diagnosing what is going on, using the new server I obtained the full query which runs against the 100,000 record table, then added the EXPLAIN keyword to the beginning of the query. The EXPLAIN SELECT output is as follows:
+----+-------------+----------------------------------+--------+------------------------------------------------------------------------------+----------------------------------------------------------+---------+---------------------------------------------------------+-------+----------------------------------------------+
| id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra |
+----+-------------+----------------------------------+--------+------------------------------------------------------------------------------+----------------------------------------------------------+---------+---------------------------------------------------------+-------+----------------------------------------------+
| 1 | SIMPLE | cog | const | PRIMARY,UI_name | UI_name | 194 | const | 1 | Using index; Using temporary; Using filesort |
| 1 | SIMPLE | cov | ref | index_option_group_id_value,index_option_group_id_name | index_option_group_id_name | 391 | const,const | 1 | Using where |
| 1 | SIMPLE | civicrm_financial_account | ALL | PRIMARY | NULL | NULL | NULL | 12 | Using join buffer |
| 1 | SIMPLE | civicrm_entity_financial_account | ref | FK_civicrm_entity_financial_account_financial_account_id | FK_civicrm_entity_financial_account_financial_account_id | 4 | micc_civicrm.civicrm_financial_account.id | 2 | Using where |
| 1 | SIMPLE | civicrm_contribution | ref | FK_civicrm_contribution_contact_id,FK_civicrm_contribution_financial_type_id | FK_civicrm_contribution_financial_type_id | 5 | micc_civicrm.civicrm_entity_financial_account.entity_id | 24322 | Using where |
| 1 | SIMPLE | civicrm_financial_type | eq_ref | PRIMARY,UI_id | PRIMARY | 4 | micc_civicrm.civicrm_contribution.financial_type_id | 1 | Using where |
| 1 | SIMPLE | civicrm_contribution_product | ref | FK_civicrm_contribution_product_contribution_id | FK_civicrm_contribution_product_contribution_id | 4 | micc_civicrm.civicrm_contribution.id | 1 | |
| 1 | SIMPLE | civicrm_product | eq_ref | PRIMARY | PRIMARY | 4 | micc_civicrm.civicrm_contribution_product.product_id | 1 | |
| 1 | SIMPLE | contact_a | eq_ref | PRIMARY,index_is_deleted | PRIMARY | 4 | micc_civicrm.civicrm_contribution.contact_id | 1 | Using where |
| 1 | SIMPLE | civicrm_entity_batch | ref | index_entity | index_entity | 199 | const,micc_civicrm.civicrm_contribution.id | 1 | |
| 1 | SIMPLE | civicrm_batch | eq_ref | PRIMARY | PRIMARY | 4 | micc_civicrm.civicrm_entity_batch.batch_id | 1 | |
| 1 | SIMPLE | civicrm_note | ref | index_entity | index_entity | 198 | const,micc_civicrm.civicrm_contribution.id | 1 | |
| 1 | SIMPLE | option_group_payment_instrument | const | UI_name | UI_name | 194 | const | 1 | Using index |
| 1 | SIMPLE | payment_instrument | ref | index_option_group_id_value,index_option_group_id_name | index_option_group_id_name | 4 | micc_civicrm.option_group_payment_instrument.id | 8 | |
| 1 | SIMPLE | option_group_contribution_status | const | UI_name | UI_name | 194 | const | 1 | Using index |
| 1 | SIMPLE | contribution_status | ref | index_option_group_id_value,index_option_group_id_name | index_option_group_id_name | 4 | micc_civicrm.option_group_contribution_status.id | 8 | |
+----+-------------+----------------------------------+--------+------------------------------------------------------------------------------+----------------------------------------------------------+---------+---------------------------------------------------------+-------+----------------------------------------------+
Out in the Extra column, for the top row I see "Using index; Using temporary; Using filesort", which that is the only row that indicates temporary... I assume that row is what is causing the tmp file to be generated.
Heavy diagnostic tool suggestions for InnoDB format databases would be greatly appreciated.
I am thankful,
Michael Lueck
Lueck Data Systems
http://www.lueckdatasystems.com/