Re: Index Skip Scan
От | Dmitry Dolgov |
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Тема | Re: Index Skip Scan |
Дата | |
Msg-id | 20200515123802.xhppukhcqemmnbqe@localhost обсуждение исходный текст |
Ответ на | Re: Index Skip Scan (Dilip Kumar <dilipbalaut@gmail.com>) |
Ответы |
Re: Index Skip Scan
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Список | pgsql-hackers |
> On Wed, May 13, 2020 at 02:37:21PM +0530, Dilip Kumar wrote: > > + if (_bt_scankey_within_page(scan, so->skipScanKey, so->currPos.buf, dir)) > + { > > Here we expect whether the "next" unique key can be found on this page > or not, but we are using the function which suggested whether the > "current" key can be found on this page or not. I think in boundary > cases where the high key is equal to the current key, this function > will return true (which is expected from this function), and based on > that we will simply scan the current page and IMHO that cost could be > avoided no? Yes, looks like you're right, there is indeed an unecessary extra scan happening. To avoid that we can see the key->nextkey and adjust higher boundary correspondingly. Will also add this into the next rebased patch, thanks!
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