We have some (internal) applications that do a fair amount of queries
(10-100 per minute), where we do complex JOIN:s on 10+ tables. The
result sets are usually a couple of hundred rows, and the main issue
with "too much effort" to cache elsewhere is simply that the table
dependencies are complicated (by these JOIN:s), which makes it a win
to have the database handle dependency tracking and caching. (That's
what a database is good for, right?)
All the best,
9 jan 2009 kl. 11.01 skrev Stephen R. van den Berg:
> External clients on the local mysql database of Roxen?
> Is that something that happens a lot in your applications?
> With respect to "too much effort"...
> The MySQL query cache is useful if one has queries with longer than
> trivial runtimes and comparatively small resultsets. The way Roxen
> uses the local MySQL database, this never happens. The queries:
> - Either have very short runtimes because they are indexed properly.
> - Or if they run longer, then the query is some kind of status/
> query which is not intended to be called a lot in rapid succession.
> - Or have very large resultsets, but should not be cached in that
> since they are not performance-critical (the problem is the large
> resultset to begin with).
> So that would imply that maintaining the query cache in MySQL is
> close to
> useless for the Roxen local database.
> Any caching needed will be done by the OS due to filesystempages
> left in RAM.
> Caching in MySQL as well, will just keep around that data in memory
Fredrik Noring, Roxen Internet Software