Re: Choice of bitmap scan over index scan

On 01/11/2010 02:53 AM, Robert Haas wrote:
> On Sun, Jan 10, 2010 at 9:04 AM, Jeremy Harris<jgh@wizmail.org>  wrote:
>> Needing to use an external (on-disk) sort method, when taking
>> only 90MB, looks odd.
[...]
> Well, you'd need to have work_mem>  90 MB for that not to happen, and
> very few people can afford to set that setting that high.  If you have
> a query with three or four sorts using 90 MB a piece, and five or ten
> users running them, you can quickly kill the box...

Oh.  That's, um, a real pity given the cost of going external.  Any hope
of a more dynamic allocation of memory resource in the future?
Within a single query plan, the number of sorts is known; how about
a sort-mem limit per query rather than per sort (as a first step)?

Cheers,
     Jeremy