From: Robert Klemme <shortcutter@...>
Date: 2009-09-15T06:11:45+09:00
Subject: Re: Pre-allocate large amount of memory?

On 14.09.2009 19:37, Carsten Gehling wrote:
> Robert Klemme wrote:
>> Maybe it's not such a good idea to read everything in memory. After
>> all, retrieving large volumes of data from disk is where RDBMS's
>> shine.
> 
> My reason for doing this is simply to avoid multiple sql-queries in a 
> recursive self-referencing datastructure. Usually this can be avoided by 
> querying the entire subset of data needed, and manipulate it in memory. 
> Unfortunately the data in question does not enable me to just query the 
> subset of data.

Is your structure strictly hierarchical (i.e. a tree) or do you need to 
query part of a graph with cycles?  If it is strictly hierarchical there 
is a solution that works for all RDBMS and in the latter case there are 
solutions for some RDBMS.

Kind regards

	robert

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