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Home -> Community -> Mailing Lists -> Oracle-L -> RE: WHERE 1 = 1 (any info on this)
I'm using that predicate in FGAC functions so the function always return
something.
An FGAC metalink note advise to this .
Stephane Paquette
Administrateur de bases de donnees
Database Administrator
Standard Life
www.standardlife.ca
Tel. (514) 499-7999 7470 and (514) 925-7187
stephane.paquette_at_standardlife.ca <mailto:stephane.paquette_at_standardlife.ca>
-----Original Message-----
Hately, Mike (LogicaCMG)
Sent: 21 octobre, 2003 07:45
To: Multiple recipients of list ORACLE-L
Morning folks,
the developers here are looking at a view with a where clause which specifies :
WHERE 1=1 AND
............... AND
............... etc.
I'd seen this used before as a way of tweaking the RBO into certain behaviours but it was years ago and my recollection is very hazy. The only explanation I've found so far is :
"the 1=1 is in there to avoid doing repetitive index scans for single rowids, when the app "knows" the result set is going to be manipulated rowid's for a large subset of the table. I would guess your DUAL/CBO example had some similar effect."
Is anyone familiar enough with this tweak to explain it ?
Cheers,
Mike
PS Maybe it'll head off some replies if I make it clear that this view hasn't been generated by code so the "1=1" isn't an accidental artifact It was custom written and is definitely supposed to have exactly this structure.
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-- Please see the official ORACLE-L FAQ: http://www.orafaq.net -- Author: Hately, Mike (LogicaCMG) INET: mike.hately_at_nedl.co.uk Fat City Network Services -- 858-538-5051 http://www.fatcity.com San Diego, California -- Mailing list and web hosting services --------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: ListGuru_at_fatcity.com (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-LReceived on Tue Oct 21 2003 - 08:49:24 CDT
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also send the HELP command for other information (like subscribing). -- Please see the official ORACLE-L FAQ: http://www.orafaq.net -- Author: Stephane Paquette INET: stephane.paquette_at_standardlife.ca Fat City Network Services -- 858-538-5051 http://www.fatcity.com San Diego, California -- Mailing list and web hosting services --------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: ListGuru_at_fatcity.com (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L
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