[Pgpool-general] suggestion: auto-detect common updatable SELECTs [SumsaultRT #3219]

[Jim C. Nasby]

On Thu, May 25, 2006 at 01:44:54PM -0400, Mark Stosberg wrote:
> Hello,
> 
> The documentation provides this warning about load balancing:
> 
>    Please note that a SELECT may modify databases by calling a
>    updatable function. In this case you should NOT use the load
>    balancing. Othewise pgpool will fail due to the contents difference
>    between the master and the secondary database. You can avoid the
>    load balancing by putting spaces or comments in the begining of the
>    query.
> 
> Are there other common cases besides "nextval" ? Could these common
> cases be automatically detected and not load-balanced?  

The problem with that is that pgpool would have to look up every
function called in the catalog to see if it was marked as VOLATILE,
which isn't exactly trivial.
-- 
Jim C. Nasby, Sr. Engineering Consultant      jnasby at pervasive.com
Pervasive Software      http://pervasive.com    work: 512-231-6117
vcard: http://jim.nasby.net/pervasive.vcf       cell: 512-569-9461