Interpreting Explain Plan (10g and Above) (Doc ID 1616894.1)

Last updated on JUNE 13, 2023

Applies to:

Oracle Database Exadata Express Cloud Service - Version N/A and later
Oracle Database Cloud Service - Version N/A and later
Oracle Database Backup Service - Version N/A and later
Oracle Database Cloud Exadata Service - Version N/A and later
Oracle Database - Enterprise Edition - Version 10.1.0.2 and later
Information in this document applies to any platform.

Purpose

This article outlines how to interpret explain plans. It is based upon an earlier document which was written in the 8i timeframe and updated to reflect more recent developments.

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For legacy information see:

<Document 46234.1> Interpreting Explain Plan

The manual also provides useful material:

Oracle® Database SQL Tuning Guide
12c Release 1 (12.1)
E15858-15
Chapter 8 Generating and Displaying Execution Plans
http://docs.oracle.com/cd/E16655_01/server.121/e15858/tgsql_genplan.htm#TGSQL271

Chapter 9 Reading Execution Plans
http://docs.oracle.com/cd/E16655_01/server.121/e15858/tgsql_interp.htm#TGSQL94618