How often is this true?  Especially, how often in actual practice is the
work of the SQL optimizer worse than a programmer.  I've read lots of bad
Image code in my days.



----- Original Message -----
From: "Shahan, Ray" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Thursday, March 08, 2001 9:31 AM
Subject: Re: Expensive RDBM Systems (Oracle)


> The reason it's true is merely a result of the SQL optimizer (and all
> RDBMS's have them) ending up doing some/all serial reads for the data
> retrieval since the optimizer can't always correctly resolve all of the
> conditions that were set at the SQL call.
>
> The IMAGE calls would be coded by the programmer, and therefore, only
> require the reads necessary to retrieve the data required.
>
>         -----Original Message-----
>         From:   Ken Hirsch [SMTP:[log in to unmask]]
>         Sent:   Thursday, March 08, 2001 8:18 AM
>         To:     [log in to unmask]
>         Subject:        Re: Expensive RDBM Systems (Oracle)
>
>         Shahan, Ray <[log in to unmask]>:
>
>
>         > Given 2 programmers, 1 for IMAGE and 1 for an RDMS, and that
both
>         > programmers are very skilled at their craft:
>         >
>         > Try coding an SQL call for several tables/indexes using
> 'inner/outer
>         joins'
>         > that also require some 'where not exists', and then maybe one or
> two 'or'
>         > conditions sprinkled with a juicy 'and' relation...not only is
it
> more
>         > difficult to code, but It's sure to kill the machine, any
> machine...every
>         > time.
>         >
>         > I know some of you will answer that IMAGE will run slow too,
given
> all the
>         > same paths, and you'd be right, but it wouldn't run near as
> slow...not
>         even
>         > close.
>
>         I have never seen evidence that this is true and I doubt it very
> much.  Why
>         do you think this is true?  In the only published article I've
seen
> where an
>         application system was converted from Image to a relational
database
> system,
>         the relational DBMS was faster.
>
>         If somebody has benchmarks showing Image is faster for some class
of
>         transactions or queries, go ahead and publish them.
>
>         The SQL has further advantages.  It is much more independent of
> database
>         structural changes than Image intrinsic calls are.
>