Re: parameterized LIKE does not use index
От | Bruno Wolff III |
---|---|
Тема | Re: parameterized LIKE does not use index |
Дата | |
Msg-id | 20050623141854.GA7505@wolff.to обсуждение исходный текст |
Ответ на | Re: parameterized LIKE does not use index (Kurt De Grave <Kurt.DeGrave@student.kuleuven.ac.be>) |
Ответы |
Re: parameterized LIKE does not use index
|
Список | pgsql-performance |
On Thu, Jun 23, 2005 at 10:33:18 +0200, Kurt De Grave <Kurt.DeGrave@student.kuleuven.ac.be> wrote: > > Now it's tempting to dream of some mechanism that could make the > database consider > replanning the query automatically once it knows the parameter, or > choose from > a set of plans depending on the parameter. In this case the general plan > was about three orders > of magnitude slower than the specialized plan. But I guess this case is > not all that common > and the developer can work around it. I remember some discussion about delaying planning until the first actual query so that planning could use actual parameters to do the planning. If you really want to have it check the parameters every time, I think you will need to replan every time. I don't know if there is a way to save some of the prepare working while doing this.
В списке pgsql-performance по дате отправления: