Re: changing sort_mem on the fly?

On Thu, Jan 27, 2005 at 06:23:05PM -0700, Michael Fuhr wrote:
> On Thu, Jan 27, 2005 at 06:23:21PM -0600, Jim C. Nasby wrote:
> >
> > If you just want to change it for one connection, you can do 'set
> > sort_mem=newvalue;'. You might need to be an admin to do it, though.
>
> Ordinary users can set sort_mem/work_mem, at least in 8.0.0 and
> earlier. Does setting that variable per session actually have an
> effect, and if it does, does allowing ordinary users to set it
> present a risk?

I ass-u-me that the setting actually takes effect. You could test it by
setting it high enough to send a system into swapping and run a query
that will use enough sort_mem. If it starts swapping, it worked. :)

Yes, there is a risk allowing ad-hoc settings; you can starve the
machine for memory.
--
Jim C. Nasby, Database Consultant decibel(at)decibel(dot)org
Give your computer some brain candy! www.distributed.net Team #1828

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