Re: SELECT slows down on sixth execution
| От | Pavel Stehule |
|---|---|
| Тема | Re: SELECT slows down on sixth execution |
| Дата | |
| Msg-id | CAFj8pRC=mWrLUcPePQ+e7xscCWGF1Q6JPsispY=zRr58hj7BfQ@mail.gmail.com обсуждение исходный текст |
| Ответ на | Re: SELECT slows down on sixth execution (Yves Dorfsman <yves@zioup.com>) |
| Список | pgsql-performance |
2015-10-17 15:29 GMT+02:00 Yves Dorfsman <yves@zioup.com>:
On 2015-10-14 03:00, Albe Laurenz wrote:
>
> You are encountering "custom plans", introduced in 9.2.
>
> When a statement with parameters is executed, PostgreSQL will not only generate
> a generic plan, but for the first 5 executions it will substitute the arguments
> and generate and execute a custom plan for that.
Wow! Thanks. I feel this should be documented a bit better.
Shouldn't this be explained in at least as much details as in your
explanation, in the sql-prepare document?
probably - some section about benefits and risks can be useful - but it is task for somebody with better English than is mine :)
Regards
Pavel
Yves.
--
http://yves.zioup.com
gpg: 4096R/32B0F416
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