Thanks to everyone for sharing your experiences. You all might want to take
a look at Article ID# 35934.1, Cost-Based Optimizer - Common Misconceptions
and Issues, available via search on Metalink.
jawa wrote in message <807c6u$52f$1_at_schbbs.mot.com>...
>Rule-based optimization runs more efficiently than cost on our application.
>The supplier told us that the version 7 optimizer has problems. Is this
>true, or is it that their application was not written by folks
knowledgeable
>of the hints and tricks designed to take full advantage of cost-based
>optimization? For instance, I ran a small benchmark report on the schema
>and found: (1) >40 tables with no index on them at all (even small tables
>without an index become the driving table), and (2) >100 foreign keys
>missing child index references (all having the potential to put locks on
the
>parent table). Could these contribute to a cost-based scenario that would
>perform poorly, or is it true that version 7's optimizer has problems like
>the supplier alleges? Has anyone else experienced a similar case study?
>
>--
>Jim Wadas
>Information Technology Solutions and Services (ITSS)
>Motorola Systems Solutions Group (SSG)
>Scottsdale, AZ 85257
>(480) 441-8196
>Jim.Wadas_at_motorola.com
>
>
>
Received on Tue Nov 09 1999 - 11:18:53 CST
