MySQL Forums
Forum List  »  InnoDB

Re: Internal Temporary tables
Posted by: Rick James
Date: February 11, 2013 11:09PM

min(max_heap_table_size, tmp_table_size) contols whether the MEMORY table is too big and must be changed to MyISAM. Other things (such as TEXT, BLOB) cause switching to MyISAM.

There are perhaps no tunables of use once it is MyISAM.

5.6.10 does a better job of avoiding hitting the limit -- it honors VARCHAR(nn) instead of turning it into CHAR(nn).

But the real solution may be in reformulating the query and/or modifying the indexes:
To assist in analyzing slow SELECTs, please provide
* SHOW CREATE TABLE tbl\G -- engine, indexes
* SHOW TABLE STATUS LIKE 'tbl'\G -- sizes
* EXPLAIN SELECT ...\G -- clues of inefficiencies
* SHOW VARIABLES LIKE '%buffer%'; -- cache size
and surround them with [ code ] and [ / code ]

Options: ReplyQuote


Subject
Views
Written By
Posted
1793
February 10, 2013 04:11PM
Re: Internal Temporary tables
919
February 11, 2013 11:09PM
808
February 20, 2013 02:30AM


Sorry, you can't reply to this topic. It has been closed.

Content reproduced on this site is the property of the respective copyright holders. It is not reviewed in advance by Oracle and does not necessarily represent the opinion of Oracle or any other party.