Re: Terminating a SETOF function call sequence - Mailing list pgsql-hackers

From Tom Lane
Subject Re: Terminating a SETOF function call sequence
Date
Msg-id 7126.1108654133@sss.pgh.pa.us
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In response to Terminating a SETOF function call sequence  (Thomas Hallgren <thhal@mailblocks.com>)
Responses Re: Terminating a SETOF function call sequence  (Thomas Hallgren <thhal@mailblocks.com>)
List pgsql-hackers
Thomas Hallgren <thhal@mailblocks.com> writes:
> My question is, what happens when the evaluator doesn't need more rows? 
> Will it:
> a) call the function with call_cntr >= max_calls?
> b) continue calling until the set is exhausted anyway?
> c) simply stop calling?

(c)

> a) seems unlikely since max_calls is set by the user, b) doesn't seem 
> very optimal, and c) would be very bad since it doesn't give me any 
> chance to release the resources that where used in order to produce the 
> rows.

This is what RegisterExprContextCallback is for.
        regards, tom lane


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