| query cache enhncement [message #560] |
Tue, 09 January 2007 11:37  |
 rhuddleston
Messages: 11
Registered: August 2006 |
Junior Member |
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se that column is updated quite a lot).
The first time a member signs in, the query in the worst cases take 20s (locking the table so other queries can't run). I guess this is fair, a lot of posts and it have to count them one by one since we haven’t indexed read.
But my question is, now that the query has run, if we run the query again a minute later the query will not take a second. Even if the table is updated, so it shouldn't be the query cache. Do mysql store sub results from the count before and use that?
Let say the member signs out and don't return for a hour. Then the query will take 20s again.The question is caching. Database blocks gets cached after they are fetched from the disk and accessing them then is very quick.
Also select itself does not lock the table (I guess you're using myISAM)- it is some concurrent updates what stall everything. okey. Then we understan
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| Re: query cache enhncement [message #561 is a reply to message #560 ] |
Tue, 09 January 2007 11:42  |
Peter
Messages: 405
Registered: August 2006 |
Senior Member
Super Guru |
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d the magic :)
Yes its myISAM. So would it runt faster if it was an innodb table?
I guess row level locking is better. Or do you have any other engine suggested?Innodb will solve your table locking problem. Table may be larger and so slower though. We have lost data from Mysql. We are trying to reconstruct the data from Query Log. Please help usHm,
Have you lost
Peter Zaitsev, MySQL Performance Expert
MySQL Performance Blog - http://www.mysqlperformanceblog.com
MySQL Consulting http://www.mysqlperformanceblog.com/mysql-consulting/
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