Steve
FYI
MSSQL7 on my workstation (1Gig Athlon, 512Mb Ram, win2K)
select count(*) from ApplicatorAction a where a.date < '2002-01-01'
go
select count(*) from ApplicatorAction a where a.date >= '2002-01-01'
go
select count(*) from ApplicatorAction a where a.date < '2002-01-01'
and exists (select 1 from ApplicatorAction b where b.date >= '2002-01-01'
and b.ApplicatorID = b.ApplicatorID and a.AllocationID = b.AllocationID)
output
-----------
558878
(1 row(s) affected)
-----------
541397
(1 row(s) affected)
-----------
15431
(1 row(s) affected)
in 17 seconds!
1/ 500K records is not a lot of data
2/ Look to your DB and indexing even IB should handle this
Neven
-----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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