Re: Is query cache used for prepared statements?

[Mark Matthews]

Peter Moore wrote:
> Hi,
>
> I know this is kind of an odd question, but when
> using a prepared statement, is the query cache
> still used?

Peter,

No, it is not. It is planned to integrate the two some day, however you might actually _lose_ performance once it's implemented, as the query would have to be 'reconstituted' from the original SQL and parameter values before the query cache coul d be used (as the query cache works at a SQL query level and uses string hasing and simple lexicographical comparison to find cached data, which is why it's very fast). Other ways of integrating the query cache with server-side prepared statements would bypass the simplicity of the hashing method used which gives the query cache its speed.

You might try _not_ using server-side prepared statements with your application, and still enabling the query cache to see whether it is a performance 'win' in your case...Simply add 'useServerPrepStmts=false' to your JDBC url.

-Mark

Mark Matthews
Consulting Member Technical Staff - MySQL Enterprise Tools
Oracle
http://www.mysql.com/products/enterprise/monitor.html