2.3 Optimizer Hints

Table of Contents Previous Next


2 Enhanced Compatibility Features : 2.3 Optimizer Hints

When you invoke a DELETE, INSERT, SELECT, or UPDATE command, the server generates a set of execution plans; after analyzing those execution plans, the server selects a plan that will (generally) return the result set in the least amount of time. The server's choice of plan is dependent upon several factors:
An optimizer hint is a directive (or multiple directives) embedded in a comment-like syntax that immediately follows a DELETE, INSERT, SELECT or UPDATE command. Keywords in the comment instruct the server to employ or avoid a specific plan when producing the result set. For information about using optimizer hints, see the Database Compatibility for Oracle Developers Guide, available at:

2 Enhanced Compatibility Features : 2.3 Optimizer Hints

Table of Contents Previous Next