Friday, October 9, 2009

Automatic SQL Tuning Features

Automatic SQL Tuning Features
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Because the manual SQL tuning process poses many challenges to the application developer, the SQL tuning process has been automated by the automatic SQL Tuning manageability features. Theses features have been designed to work equally well for OLTP and Data Warehouse type applications

ADDM

Automatic Database Diagnostic Monitor (ADDM) analyzes the information collected by the AWR for possible performance problems with the Oracle database, including high-load SQL statements.

SQL Tuning Advisor

SQL Tuning Advisor allows a quick and efficient technique for optimizing SQL statements without modifying any statements.

SQL Tuning Sets

When multiple SQL statements are used as input to ADDM or SQL Tuning Advisor, a SQL Tuning Set (STS) is constructed and stored. The STS includes the set of SQL statements along with their associated execution context and basic execution statistics.

SQLAccess Advisor

In addition to the SQL Tuning Advisor, Oracle provides the SQLAccess Advisor that provides advice on materialized views, indexes, and materialized view logs. The SQLAccess Advisor helps you achieve your performance goals by recommending the proper set of materialized views, materialized view logs, and indexes for a given workload. In general, as the number of materialized views and indexes and the space allocated to them is increased, query performance improves. The SQLAccess Advisor considers the trade-offs between space usage and query performance and recommends the most cost-effective configuration of new and existing materialized views and indexes.

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