Re: Strange issue with GiST index scan taking far too long

Tom Lane wrote:

> Well, yeah, because the first thing it does is pg_detoast_datum.
> Just as a cross-check, try changing it to copy the value without
> forcibly detoasting --- I'll bet it's still slow then.

Yeah, that appears to be exactly the case. After some grepping through
various header files I came up with this alternative:

PG_FUNCTION_INFO_V1(LWGEOM_mcatest);
Datum LWGEOM_mcatest(PG_FUNCTION_ARGS)
{
struct varlena *pgl = PG_GETARG_RAW_VARLENA_P(0);
void *mem;

// Copy somewhere else
mem = palloc(VARSIZE_EXTERNAL(pgl));
memcpy(mem, pgl, VARSIZE_EXTERNAL(pgl));

PG_RETURN_POINTER(mem);
}

...and of course, this now takes the slower runtime of 2.5s.

ATB,

Mark.

--
Mark Cave-Ayland
Sirius Corporation - The Open Source Experts
http://www.siriusit.co.uk
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