Re: ANALYZE patch for review

"Mark Cave-Ayland" <m(dot)cave-ayland(at)webbased(dot)co(dot)uk> writes:
> Having been working with the PostGIS team to implement a custom analyze
> routine for R-Tree selectivity, we have a question regarding the new
> vacuum_delay_point() which is present in analyze.c. Is it the
> responsibility of the programmers to remember to do a
> vacuum_delay_point() before calling the fetch_func(), or would it be
> better to move the vacuum_delay_point() into std_fetch_func()?

It's probably not really necessary to call vacuum_delay_point in the
analysis routine, unless you are contemplating extremely expensive
analysis. If you did have an expensive loop, would std_fetch_func
necessarily be called inside it? It seems inappropriate to me to put
vacuum_delay_point inside std_fetch_func --- it's the analysis
programmer's business to understand whether it must be called, and if
so where's an appropriate place.

regards, tom lane