| From: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
|---|---|
| To: | Thomas Lockhart <lockhart(at)alumni(dot)caltech(dot)edu> |
| Cc: | Mike Mascari <mascarm(at)mascari(dot)com>, pgsql-hackers(at)postgresql(dot)org |
| Subject: | Re: Weird function behavior from Sept 11 snapshot |
| Date: | 2000-09-12 15:14:21 |
| Message-ID: | 7490.968771661@sss.pgh.pa.us |
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| Lists: | pgsql-hackers |
Thomas Lockhart <lockhart(at)alumni(dot)caltech(dot)edu> writes:
> How about using int8 for the accumulator (on machines which support it
> of course)? Falling back to float8 or numeric on other machines?
int8 would still pose some overflow risk (at least for int8 input),
and would likely be no faster than a float8 implementation, since
both would require palloc().
Your test suggests that the performance differential is *at most*
2X --- probably much less in real-world situations where the disk
pages aren't already cached. I can't get excited about introducing
platform-dependent behavior and overflow risk for that. If it were
10X then I would, but right now I think we are OK as is. I think
any speedup efforts here would be better put into making NUMERIC
ops go faster ...
regards, tom lane
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