CBO in 10g

From: BP <brian.peasey_at_gmail.com>
Date: Thu, 13 Oct 2005 22:43:16 -0500
Message-ID: <ff2080f40510132043v6a9f8c04u855713500bec5d85@mail.gmail.com>

Hi Guys,

I received this today from one of our developers, who in turn got it from Progress. Is this true? I thought CBO was default starting in 8i and in 10g stats are automatically collected.

N.B. 'Dataserver' is their product used to translate progress code to SQL.

Brian Peasey

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Be careful of Oracle 10g:
A) the default optimizer under 10g is now Cost-Based (CBO); it used to be Rules-Based (RBO) under 9i. If your database statistics aren't up to date then the CBO can easily choose table scans. We are in the process of writing a whitepaper on this and it should available via PSDN soon (use the above hyperlink).
Anyone on OpenEdge 10 against Oracle 10g should get the latest OpenEdge service pack as there was an issue related to Function Based Index usage that could cause unnecessary Table Scans.

B) Try to upgrade to at least Oracle 10g (10.1.0.4) - there is an Oracle bug that intermittently generates an Oracle 600 error

Simon Epps
DataServer Product Manager
Progress Software
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Received on Thu Oct 13 2005 - 22:45:47 CDT