RE: anyone know how to do a join where the data can be different
Date: Wed, 11 Jun 2008 12:32:08 -0500
While the queries from both Mark and David will return the same results, David's query provides the one that has the potential to perform better. If you put an index on datefield, only his version will use it.
Sorry, Russ, but yours is not correct. For example if tab1.datefield has time value of 21:59 and tab2.datefield has a time value of 22:01, then these two times are within 5 seconds, but...
abs(59-01) = 58
58 is not <= 5
From: oracle-l-bounce_at_freelists.org [mailto:oracle-l-bounce_at_freelists.org] On Behalf Of Russ Brewer Sent: Wednesday, June 11, 2008 10:02 AM
Cc: Mark.Bobak_at_proquest.com; ricks12345_at_gmail.com; oracle-l_at_freelists.org Subject: Re: anyone know how to do a join where the data can be different
What about something like:
From tab1, tab2
where ABS(TO_NUMBER(TO_CHAR(tab1.datefield,'SS')) - TO_NUMBER(TO_CHAR(tab2.datefield,'SS'))) <= 5;
On 5/14/08, David Aldridge <david_at_david-aldridge.com<mailto:david_at_david-aldridge.com>> wrote: It might be more efficient to do something like ...
From tab1, tab2
And tab1.datefield between tab2.datefield) - 5/86400 and tab2.datefield) + 5/86400
- Original Message ---- From: "Bobak, Mark" <Mark.Bobak_at_proquest.com<mailto:Mark.Bobak_at_proquest.com>> To: "ricks12345_at_gmail.com<mailto:ricks12345_at_gmail.com>" <ricks12345_at_gmail.com<mailto:ricks12345_at_gmail.com>>; "oracle-l_at_freelists.org<mailto:oracle-l_at_freelists.org>" <oracle-l_at_freelists.org<mailto:oracle-l_at_freelists.org>> Sent: Wednesday, May 14, 2008 2:41:34 PM Subject: RE: anyone know how to do a join where the data can be different
From tab1, tab2
And abs(tab1.datefield-tab2.datefield) <= 5/86400;
Mark J. Bobak
Senior Database Administrator, System & Product Technologies ProQuest
789 E. Eisenhower, Parkway, P.O. Box 1346 Ann Arbor MI 48106-1346
+1.734.997.4059 or +1.800.521.0600 x 4059 mark.bobak_at_proquest.com<mailto:mark.bobak_at_il.proquest.com> www.proquest.com<http://www.proquest.com/> www.csa.com<http://www.csa.com/>
From: oracle-l-bounce_at_freelists.org<mailto:oracle-l-bounce_at_freelists.org> [mailto:oracle-l-bounce_at_freelists.org<mailto:oracle-l-bounce_at_freelists.org>] On Behalf Of Rick Ricky
Sent: Wednesday, May 14, 2008 2:32 PM
To: oracle-l_at_freelists.org<mailto:oracle-l_at_freelists.org> Subject: anyone know how to do a join where the data can be different
I have two different data sets. They come from two different feeds.
I have an ID field that I can join on that is the same in both. However, I have a date field in each. Here is the catch, the dates can be up to 5 second apart.
So I have
from tab1, tab2
and tab1.datefield is with in 5 seconds of tab2.datefield
anyone know a way to do this without a lot of complex pl/sql?
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http://www.freelists.org/webpage/oracle-l Received on Wed Jun 11 2008 - 12:32:08 CDT