What is rule based optimization in Oracle Apps?

Just before proceeding to details, Optimization is at the database level and not a concept in APPS. Performance tuning is a key aspect of any deliverable. Optimising your query to produce results in less possible time is much desirable in any deliverable. Optimization is done in 2 ways. 1) Rule Based optimization and 2) Cost Based Optimization. Rule Based Optimization is where there are pre-defined set of rules based on which your query will use them to fetch the results. For example. Any index on a table used in the query though not used in the query has to be applied because of the rule defined. This will increase the execution time of the query. This is an old method followed by oracle earlier. They have now moved it to cost based optimization. Hope this clear your question. Let me know if you need any additional details. Thanks Krishna Kishore read less

Basically, the RBO used a set of rules to determine how to execute a query. If an index was available on a table, the RBO rules said to always use the index. There are some cases where the use of an index slowed down a query. Oracle Corporation strongly advises the use of cost-based optimization. Rule-based optimization will be deprecated in a future release. read less