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Re: Oracle position on hints

From: Chuck Hamilton <chuckh_at_softhome.net>
Date: Mon, 10 Mar 2003 07:19:10 -0800
Message-ID: <F001.005647AE.20030310071910@fatcity.com>


Congratulations Connor. May the day exceed all your expectations. If you figure out how to attach a piece of cake to an email, send me one. :-)

--
Chuck

----- Original Message -----
To: "Multiple recipients of list ORACLE-L" <ORACLE-L_at_fatcity.com>
Sent: Saturday, March 08, 2003 8:53 PM



> Just to add my meaningless diatribe to the discussion,
> I think that there are "good" hints and "bad" hints.
>
> For example, first_rows(n) is a good hint, in that you
> are giving the optimizer more information as to what
> your motivations are for this query, without stifling
> it into a choice that may not be appropriate down the
> track.
>
> Hints such as index(tab,idx) are "bad" hints, because
> you are more exposed to grief. If the index is
> renamed, then its no longer a hint. If the data
> distribution changes, or the index is rebuilt in
> reverse or compressed, then it may no longer be a good
> option, etc.
>
> In terms of the vendor speak of "hints imply weak
> optimizer" I think thats nonsense. Having worked with
> DB2 in the past, nothing used to be more irritating
> then coming up with bizarre convolutions on an
> otherwise simple SQL to ensure that certain indexes
> were or were not chosen.
>
> Cheers
> Connor
>
> PS - Its probably a little sad that I'm chit-chatting
> on hints on the morning of my wedding day, but hey,
> you gotta pass the time somehow whilst the other half
> is getting the hair and makeup done :-)
>
>
>
> --- "Khedr, Waleed" <Waleed.Khedr_at_FMR.COM> wrote: >
> It's like the Auto-pilot
> >
> > -----Original Message-----
> > To: Multiple recipients of list ORACLE-L
> > Sent: 3/8/03 2:13 PM
> >
> > Stephane
> > I don't see how Oracle could ever have an
> > official position on hints.
> > If
> > they say hints are going away, many developers
> > panic. If they say hints
> > are
> > great, then Oracle competitors will claim Oracle has
> > a bad optimizer.
> > A key political issue in some shops is "Using
> > hints makes our code
> > Oracle-specific". My reply is that hints are only
> > comments that another
> > database will ignore.
> >
> > Dennis Williams
> > DBA, 40%OCP, 100% DBA
> > Lifetouch, Inc.
> > dwilliams_at_lifetouch.com
> >
> >
> > -----Original Message-----
> > Sent: Friday, March 07, 2003 12:19 PM
> > To: Multiple recipients of list ORACLE-L
> >
> >
> > Hi,
> >
> > I have to write a SQL and PL/SQL guide for our
> > developpers.
> > Some are good but most of them can use help.
> >
> > I'm not a big fan of hints except for insert append,
> > I used them only if
> > I
> > really need to.
> >
> > In last october I went to a 3 days DB2 UDB course,
> > unless I miss
> > something
> > there are no hint with DB2 UDB.
> > So I was thinking that when the Oracle optimiser
> > would be more mature
> > maybe
> > hints would go away.
> >
> > I just want to know what is Oracle direction with
> > hints.
> >
> > TIA
> >
> > Stephane
> >
> >
> > -----Original Message-----
> > Robert - IL
> > Sent: Friday, March 07, 2003 12:01 PM
> > To: Multiple recipients of list ORACLE-L
> >
> >
> > This is facinating, where does this come from? This
> > is the second time
> > in a
> > week that I've heard this statement being made by
> > someone. Hints will
> > never
> > go away IMHO, and Oracle continues to add more and
> > more of them. I was
> > told
> > by someone at a client site that they were told by
> > an Oracle instructor
> > that
> > they should not use hints in 9i....
> >
> > RF
> >
> > -----Original Message-----
> > To: Multiple recipients of list ORACLE-L
> > Sent: 3/7/2003 10:04 AM
> >
> > Hi,
> >
> > Does Oracle have an official position on hints ?
> > Will they go away as the optimiser is becoming
> > bettre or they are there
> > to stay ?
> >
> > TIA
> >
> >
> >
> > Stephane Paquette
> >
> >
> > Administrateur de bases de donnees
> >
> > Database Administrator
> >
> > Standard Life
> >
> > www.standardlife.ca
> >
> > TÚl. (514) 925-7187
> >
> > stephane.paquette_at_standardlife.ca
> > <mailto:stephane.paquette_at_standardlife.ca>
> >
> >
> > --
> > Please see the official ORACLE-L FAQ:
> > http://www.orafaq.net
> > --
> > Author: Freeman Robert - IL
> > INET: FREEMANR_at_tusc.com
> >
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> > Author: DENNIS WILLIAMS
> > INET: DWILLIAMS_at_LIFETOUCH.COM
> >
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> > Author: Khedr, Waleed
> > INET: Waleed.Khedr_at_FMR.COM
> >
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>
> =====
> Connor McDonald
> web: http://www.oracledba.co.uk
> web: http://www.oaktable.net
> email: connor_mcdonald_at_yahoo.com
>
> "GIVE a man a fish and he will eat for a day. But TEACH him how to fish,
and...he will sit in a boat and drink beer all day"
>
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> Please see the official ORACLE-L FAQ: http://www.orafaq.net
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> Author: =?iso-8859-1?q?Connor=20McDonald?=
> INET: hamcdc_at_yahoo.co.uk
>
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-- Please see the official ORACLE-L FAQ: http://www.orafaq.net -- Author: Chuck Hamilton INET: chuckh_at_softhome.net 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 (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).
Received on Mon Mar 10 2003 - 09:19:10 CST

Original text of this message

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