In optimizing our Oracle 7.2 queries, we have several questions:
- What decent references or literature exists around there regarding the
optimization of:
joins spanning several tables (the oracle fine-tuning courses so far
essentially only discussed 2-table join optimizations in detail), in
particular outer joins
subqueries
the use of rule-based vs cost-based optimizations
- When switching from rule-based to cost-based optimization some queries
involving subqueries performed MUCH slower. Is this typical of subqueries
or do we need to take other factors into account?
- Is there any gain to be had whatsover from modelling our own null
records and null values in order to avoid the Oracle outer joins?
- To which degree does the size of shared caches (queries, cursors) impact
performance, for instance by deviating from the optimum setting as
recommended by Oracle?
Thanks,
Michel Tilman
Michel Tilman
Unisys Belgium n.v.
E-mail: mtilman_at_argo.be
Received on Fri Dec 13 1996 - 00:00:00 CST
