Re: Database is extremely slow

"Sybrand Bakker" <gooiditweg_at_sybrandb.demon.nl> wrote in message news:chljfv46m69gv1vob4mpkkvgqvlicstltm_at_4ax.com...
> On Wed, 25 Jun 2003 17:20:38 +0100, "Niall Litchfield"
> <n-litchfield_at_audit-commission.gov.uk> wrote:
>
> >However 7.3.4 was pretty much the
> >first production release with a CBO in it
>
> Completely incorrect. CBO was available from 7.1. However it was so
> lousy at that time that no one used. Stating though 7.3.4 is the first
> release with CBO 1.x in it is just plain untrue.

I phrased it extremely badly indeed.

I should have said that 7.3.4 was the first release that had a 'usable' CBO in it. And of course many folk will recognize that 'usable' is not the same as 'useful'.

Tim Gorman's paper (The search for intelligent life in the cost based optimizer) suggests that the CBO was first made available in 7.0 and I have seen suggestions that the code existed (in distinctly non-production form) in 6.

What *did* start in 7.1 was adding features and not making the RBO aware of them.

Never the less it is clearly wrong to say that the CBO first started in 7.3.4 and I unreservedly apologize for giving that impression. I should have said something along the lines of "The CBO in 7.3.4 was very primitive and unreliable - you can use it but it wasn't advisable"

-- 
Niall Litchfield
Oracle DBA
Audit Commission UK
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