Re: performance of count(*)
От
Scott Ribe
Тема
Re: performance of count(*)
Дата
Msg-id
15F17483-3C8D-4D47-896A-96BFFA24B73C@elevated-dev.com
Ответ на
Re: performance of count(*) (Andrew Sullivan)
Список
Дерево обсуждения
performance of count(*) Scott Ribe <scott_ribe@elevated-dev.com>
Re: performance of count(*) Andrew Sullivan <ajs@crankycanuck.ca>
Re: performance of count(*) Tomas Vondra <tv@fuzzy.cz>
Re: performance of count(*) Scott Ribe <scott_ribe@elevated-dev.com>
Re: performance of count(*) Andrew Sullivan <ajs@crankycanuck.ca>
Re: performance of count(*) Scott Ribe <scott_ribe@elevated-dev.com>
On May 6, 2011, at 4:15 PM, Andrew Sullivan wrote: > Yeah, in that case the HOT suggestions are very important. I strongly > recomment you experiment in a test system with real data and > pathological cases in particular, in order to see what happens when > the outlier cases inevitably, Murphy willing, crop up. That's not to > say you should arrange your plans for them, but forewarned is > forearmed. Again thanks. The HOT tip led me down the road of paying attention to my indexes, which led me to a nice realization about how to shrink the overall footprint of the materialized aggregates ;-) Which led me to a technique to seriously minimize updates... I didn't have to worry about bloat too much--overall activity level is not huge; the possibility of collisions on updates is mostly because users tend to work on the same very small (but ever-shifting) subset of the data at the same time, but now I think I'm really set! -- Scott Ribe scott_ribe@elevated-dev.com http://www.elevated-dev.com/ (303) 722-0567 voice
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