From: Martijn Tonies
Date: September 3 2004 12:37pm
Subject: Re: Fetch-on-demand
List-Archive: http://lists.mysql.com/mysql/172049
Message-Id: <040301c491b2$c8b35a60$0a02a8c0@martijn>
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Hi,

> > Does MySQL support fetch-on-demand of resultsets?
> >
> > And if so, does it support multiple cursors fetching on the same time
> > using the same connection?
> >
> > If so, is it thread safe?
>
> What do you mean "fetch-on-demand"? I've never heard this term before.
Since
> every fetch takes place when your program calls for it, isn't every fetch
> already "fetch-on-demand"?

There are two ways to fetch a resultset -

1) fetch the entire resultset, close the handle (or whatever) and
cache the resultset locally so you can do your stuff.

2) keep the resultset open and fetch rows on a need-to-handle
basis. Sometimes also called a "server side cursor". Usually
forward only.

From my understanding, I believe MySQL can do (2), but my
question was if it can do (2) for multiple cursors at the same time,
or having a cursor open and execute other statements, on the
same connection.

And if so, if this is multi-thread-safe on a connection/network
level.

With regards,

Martijn Tonies
Database Workbench - developer tool for InterBase, Firebird, MySQL & MS SQL
Server.
Upscene Productions
http://www.upscene.com