The following concepts were covered in this module:

1. Oracle provides a standard ANSI SQL for database access, and has provided a wealth of built-in functions to improve SQL productivity.
2. SQL tuning is one of the single most important tuning techniques that can be used to tune an Oracle database.
3. Oracle provides a set of tools to assist in tuning SQL, including EXPLAIN PLAN, TKPROG and SQL Analyzer.
4. Oracle has two optimizer modes. Rule-based optimization is the oldest method and relies on heuristics to determine access paths. The cost-based optimizer is a later development and relies on table and index statistics to formulate access plans to data.
5. The EXPLAIN PLAN utility is the primary method for viewing the underlying access path to Oracle tables and indexes.
6. Oracle provides hints that can be added to standard SQL to change the access path to data.