add "distinct" to your query so you on get one of each field content. this
should reduce the amount of records processed by the query.

ie select distinct field1 from atable where...

Maurice

-----Original Message-----
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] Behalf Of Steve Aish
Sent: Thursday, 20 May 2004 2:31 p.m.
To: [EMAIL PROTECTED]
Subject: [DUG] Dealing with large amounts of data - comparing


Hi y'all,

I have a database that records approx 500,000 records per week in one
table.

I want to compare week 1 and week 2 for example to see which of a
certain field are in week 1 but not in week 2.

I am using Interbase.

I thought of running a query (until my pc ran out of hard drive space
with the temp file size).

I thought the easiest (although probably not the best) way would be to
fill in a stringlist (I am only worried about 1 field) with week 1 and
then fill another stringlist with week 2 and then compare them.  I just
open a query with one field in it and iterate through the query and

List.Add(Query1.FieldByName('Field').asString);

This runs out of memory after 200,000 records or so.  It is not the
string list running out of memory - it is the Query1... ??? Confuses
me.

Any ideas?


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