Re: strange OOM errors with EXECUTE in PL/pgSQL

Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> writes:
> The reason this fails is that you've got a half-megabyte source string,
> and each of the 11000 plans that are due to be created from it saves
> its own copy of the source string. Hence, 5500 megabytes needed just
> for source strings.
>
> We could possibly fix this by inventing some sort of reference-sharing
> arrangement (which'd be complicated and fragile) or by not storing the
> source strings with the plans (which'd deal a serious blow to our
> ability to provide helpful error messages). Neither answer seems
> appealing.

I don't readily see how complicated and fragile it would be, it looks
like a hash table of symbols pointing to source strings and a reference
counting, and each plan would need to reference that symbol. Now maybe
that's what you call complicated and fragile, and even if not, I'm not
really sure it would pull its weight. The use case of sending over and
over again *in a given session* the exact same query string without
using PREPARE/EXECUTE looks like quite tiny.

--
Dimitri Fontaine
http://2ndQuadrant.fr PostgreSQL : Expertise, Formation et Support