Oracle FAQ Your Portal to the Oracle Knowledge Grid
HOME | ASK QUESTION | ADD INFO | SEARCH | E-MAIL US
 

Home -> Community -> Usenet -> c.d.o.misc -> Re: different SQL approaches

Re: different SQL approaches

From: Daniel Morgan <damorgan_at_x.washington.edu>
Date: Fri, 15 Oct 2004 18:54:50 -0700
Message-ID: <1097891778.770167@yasure>


Andy Hassall wrote:

> On Thu, 14 Oct 2004 18:02:32 -0700, Daniel Morgan <damorgan_at_x.washington.edu>
> wrote:
>
>

>>And then, of course, there is the issue of bind variables as neither
>>statement should ever be written for any reason. 

>
>
> Problem with saying never is there's usually exceptions. You're saying that
> there should never be literals in SQL statements, and they should always be
> bind variables even when they're constants? Not enough information to say
> whether the OP's query makes sense or not with either of the two values
> changing, so maybe they're candidates for bind variables, but maybe not.
>
> And what about the cases where using bind variables produces worse plans? e.g.
> bind variable peeking producing one plan for a skewed-value column, where a
> later execution with a different value could benefit from a different plan.
>
> http://download-west.oracle.com/docs/cd/B14117_01/server.101/b10752/optimops.htm#79381
>
> http://asktom.oracle.com/pls/ask/f?p=4950:8:::::F4950_P8_DISPLAYID:7832114438832#9915391826680
>
> Certainly bind variables are appropriate for the variable values in an SQL
> statement the majority of time - but there are reasons for exceptions.

And the 'reasons' are?

Please don't keep us in suspense.

I've always had an aversion to filling the cache with duplicate statements ... is there some reason why I might want to do so?

-- 
Daniel A. Morgan
University of Washington
damorgan_at_x.washington.edu
(replace 'x' with 'u' to respond)
Received on Fri Oct 15 2004 - 20:54:50 CDT

Original text of this message

HOME | ASK QUESTION | ADD INFO | SEARCH | E-MAIL US