Query Plan

Related Terms

A query plan, also known as query execution plan, is an ordered set of steps used to access information in a SQL relational database management system.

This is a specific case of the relational model concept of access plans.

Since SQL is declarative, there are typically a large number of alternative ways to execute a given query, with widely varying performance.

When a query is submitted to the database, the query optimizer evaluates all of the different possible plans for executing the query and returns what it considers the best alternative.