From: Alan Chen <alan@...>
Date: 2001-12-07T14:26:56+09:00
Subject: [ruby-talk:27785] Re: DBI and large result sets

Well, you could declare a cursor in SQL. I believe its a standard
SQL92 feature.  PostgreSQL supports it.  I don't know about MySQL.

On Fri, Dec 07, 2001 at 01:26:31PM +0900,  JamesBritt wrote:
> I'm starting to use Ruby DBI, and I'm wondering about its use when processing
> very large result sets.
> 
> Given that DBI sits on top of various DB drivers, is there some way to use DBI
> to run a query and process each record set without necessarily having to hold
> the entire result set in memory?  Or is DBI too abstract to allow you to make
> any assumptions about that?
> 
> DBI::StatementHandle has fetch_many, but I think it works on a local store of
> the entire result set (whereas I want it to pull the data from the database
> only as I request a number of rows).
> 
> Basically I want the SQL query to behave like a stream, not a single, huge,
> chunk o' data, but not have to tie the code to a specific database (if
> possible).
> 
> 
> Thanks,
> 
> 
> James
> 
> 

-- 
Alan Chen
Digikata LLC
alan@digikata.com
http://digikata.com