Re: [PERFORMANCE] slow small delete on large table

After a long battle with technology, pgsql@bluepolka.net ("Ed L."), an earthling, wrote:
> On Monday February 23 2004 10:23, Tom Lane wrote:
>> "Ed L." <pgsql@bluepolka.net> writes:
>> Depending on the size of mytable, you might need an "ANALYZE doomed"
>> in there, but I'm suspecting not.  A quick experiment suggests that
>> you'll get a plan with an inner indexscan on mytable.key, which is
>> exactly what you need.
>
> I didn't mention I'd written a trigger to do delete N rows on each new
> insert (with a delay governor preventing deletion avalanches).  The
> approach looks a little heavy to be done from within a trigger with the
> response time I need, but I'll try it.  Cantchajust toss in that "limit N"
> functionality to delete clauses?  How hard could that be?  ;)

It's nonstandard, which will get you a certain amount of opposition
"for free;" the problem with nonstandard behaviour is that sometimes
the implications haven't been thought out...

>> See also Chris Browne's excellent suggestions nearby, if you are willing
>> to make larger readjustments in your thinking...
>
> I did a search for articles by Chris Browne, didn't see one that
> appeared relevant.  What is the thread subject to which you refer?

It's in the same thread.  I suggested having a daemon running a cursor
(amounting to a slightly more expensive version of Tom's "doomed temp
table" approach), or using "rotor" tables where you could TRUNCATE a
table every few days which would be _really_ cheap...
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