Re: JDBC best practice

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От Kris Jurka
Тема Re: JDBC best practice
Дата
Msg-id Pine.BSO.4.56.0503282134260.30526@leary.csoft.net
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Ответ на JDBC best practice  ("Dave Held" <dave.held@arrayservicesgrp.com>)
Список pgsql-performance

On Mon, 28 Mar 2005, Dave Held wrote:

> I'm using a Postgres table as the data source for a JTable in a Java
> app.  Where rs_ is a RecordSet object.  What I'm wondering is whether
> it's better to call absolute() or relative() or next()/previous().  If
> absolute() is the slowest call, then I can cache the last row fetched
> and move relative to that.
>
> My suspicion is that next()/previous() is much faster than absolute()
> when the record to be fetched is very near the last record fetched.  I
> haven't actually tried it, but I'd like some insight if others can
> already answer this question based on knowledge of the server side
> and/or the JDBC driver.

There are two types of ResultSets that can be returned by the JDBC driver.
One is backed by a cursor and can only be used for TYPE_FORWARD_ONLY
ResultSets so it is not really applicable to you.  The other method
retrieves all results at once and stashes them in a Vector.  This makes
next, absolute, and relative positioning all equal cost.

Kris Jurka

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