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Question about Handler_write
Posted by: Sebastien Caisse
Date: February 09, 2006 09:42AM

Here is the SHOW GLOBAL STATUS LIKE 'Handler_'; query for a server running for about 2 weeks:
"Variable_name","Value"
"Handler_commit","4991"
"Handler_delete","0"
"Handler_discover","0"
"Handler_prepare","0"
"Handler_read_first","1311"
"Handler_read_key","76594321"
"Handler_read_next","92577648"
"Handler_read_prev","0"
"Handler_read_rnd","11350911"
"Handler_read_rnd_next","16147952"
"Handler_rollback","96"
"Handler_savepoint","0"
"Handler_savepoint_rollback","0"
"Handler_update","2441"
"Handler_write","13448530"

Now given the front-end being Access, it's more or less to be expected that the queries built by it don't properly use the indexes and thus read_rnd and read_rnd_next have (well, to my eyes) high values; and this is probably a good place to optimize...

However what worries me more right now is that Handler_write seems to increase really fast yet in the program itself there are very few inserts being done... (around 500rows/s)

Although perhaps this includes INSERTs done on the mysql schema and/or temp tables created because of sorting? In the latter case, pretty much everything involves sorting in my select queries which would explain the massive INSERTs? [In that line of thought, Created_tmp_table increases at about 5tables/s]



Edited 2 time(s). Last edit at 02/09/2006 09:46AM by Sebastien Caisse.

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