left table: In an outer join, the table specified on the left side of the OUTER JOIN keywords (in ANSI SQL syntax).
right table: In an outer join, the table specified on the right side of the OUTER JOIN keywords (in ANSI SQL syntax).
The following concepts were covered in this module:
- Oracle provides a standard ANSI SQL for database access, and has provided a wealth of built-in functions to improve SQL productivity.
- SQL tuning is one of the single most important tuning techniques that can be used to tune an Oracle database.
- Oracle provides a set of tools to assist in tuning SQL, including EXPLAIN PLAN, TKPROG and SQL Analyzer.
- 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.
- The EXPLAIN PLAN utility is the primary method for viewing the underlying access path to Oracle tables and indexes.
- Oracle provides hints that can be added to standard SQL to change the access path to data.