Re: Minmax indexes
| От | Jeff Janes |
|---|---|
| Тема | Re: Minmax indexes |
| Дата | |
| Msg-id | CAMkU=1xiBuZnhtwab8f6NXDCQNFu+VHd9gb4ZUqvYBXfB6LXjg@mail.gmail.com обсуждение исходный текст |
| Ответ на | Re: Minmax indexes ("Erik Rijkers" <er@xs4all.nl>) |
| Список | pgsql-hackers |
On Mon, Nov 11, 2013 at 12:53 AM, Erik Rijkers <er@xs4all.nl> wrote:
On Fri, November 8, 2013 21:11, Alvaro Herrera wrote:> [minmax-7.patch]
>
> Here's a version 7 of the patch, which fixes these bugs and adds
> opclasses for a bunch more types (timestamp, timestamptz, date, time,
> timetz), courtesy of Martín Marqués. It's also been rebased to apply
> cleanly on top of today's master branch.
>
> I have also added a selectivity function, but I'm not positive that it's
> very useful yet.
>
The earlier errors are indeed fixed; now, I've been trying with the attached test case but I'm unable to find a query that
improves with minmax index use. (it gets used sometimes but speedup is negligable).
Your data set seems to be completely random. I believe that minmax indices would only be expected to be useful when the data is clustered. Perhaps you could try it on a table where it is populated something like i+random()/10*max_i.
Cheers,
Jeff
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