Tom Lane wrote:
Jack Orenstein <jao@xxxxxxxxxxxx> writes:
I'm missing something very basic. If I do this:
Datum foobar(PG_FUNCTION_ARGS)
{
...
void* plan = SPI_prepare(...);
void* saved_plan = SPI_saveplan(plan);
...
}
then how can I access the saved plan in a later invocation of foobar?
It's up to you to save the pointer somewhere where you can find it again
when you need it. If there's only one interesting plan, use a static
variable. Otherwise, you'll need some sort of data structure to map
from what-you-need to the-plan-that-does-it. You can find examples of
these approaches in the PG sources (from memory, ruleutils.c has some
examples of the former approach while ri_triggers.c does the latter).
OK, that makes sense. It was use of the term "local variable" that threw
me.
Assigning SPI_prepare output to a local makes sense. Assigning
SPI_saveplan output to a static makes sense. But I don't see
the point in assigning SPI_saveplan output to a local, yet
that's what one case the doc specifically mentions.
Jack Orenstein
