Re: Large # of rows in query extremely slow, not using

Поиск
Список
Период
Сортировка
От Kris Jurka
Тема Re: Large # of rows in query extremely slow, not using
Дата
Msg-id Pine.BSO.4.56.0409231840280.18935@leary.csoft.net
обсуждение исходный текст
Ответ на Re: Large # of rows in query extremely slow, not using index  (Stephen Crowley <stephen.crowley@gmail.com>)
Список pgsql-performance

On Thu, 23 Sep 2004, Stephen Crowley wrote:

> Thanks for the explanation. So what sort of changes need to be made to
> the client/server protocol to fix this problem?

The problem is that there is no way to indicate why you are using a
particular statement in the extended query protocol.  For the JDBC driver
there are two potential reasons, streaming a ResultSet and using a server
prepared statement.  For the streaming as default case you desire there
needs to be a way to indicate that you don't want to create a generic
server prepared statement and that this query is really just for one time
use, so it can generate the best plan possible.

Additionally you can only stream ResultSets that are of type FORWARD_ONLY.
It would also be nice to be able to specify scrollability and holdability
when creating a statement and the offset/direction when streaming data
from a scrollable one.

Kris Jurka

В списке pgsql-performance по дате отправления:

Предыдущее
От: Stephen Crowley
Дата:
Сообщение: Re: Large # of rows in query extremely slow, not using index
Следующее
От: "Josh Berkus"
Дата:
Сообщение: Re: Caching of Queries