roxen.lists.roxen.general

Subject Author Date
Re: Lots of patches that can be integrated into Roxen 5.0 in a heartbeat Fredrik Noring <noring[at]roxen[dot]com> 12-01-2009
Hi Stephen,

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,
Fredrik

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/ 
> maintenance
>  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  
> case,
>  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  
> *twice*.

-- 
Fredrik Noring, Roxen Internet Software