Re: Inlining comparators as a performance optimisation

On 21.09.2011 18:46, Tom Lane wrote:
> Well, we'd have to negotiate what the API ought to be. What I'm
> envisioning is that datatypes could provide alternate comparison
> functions that are designed to be qsort-callable rather than
> SQL-callable. As such, they could not have entries in pg_proc, so
> it seems like there's no ready way to represent them in the catalogs.

Quite aside from this qsort-thing, it would be nice to have versions of
all simple functions that could be called without the FunctionCall
overhead. So instead of:

FunctionCall2(&flinfo_for_int4pl, 1, 2)

you could do simply

int4pl_fastpath(1,2)

I'm not sure how big an effect this would have, but it seems like it
could shave some cycles across the system.

We could have an extended version of the PG_FUNCTION_INFO_V1 macro that
would let you register the fastpath function:

PG_FUNCTION_INFO_V1(int4pl, int4pl_fastpath);

--
Heikki Linnakangas
EnterpriseDB http://www.enterprisedb.com