SORT GROUP BY
Short Description
SORT GROUP BY is an aggregation step which allows values to be put in order and made unique where a unique index is not in use.
Detailed Description​
The step will be seen when the GROUP BY
clause is used with aggregate functions such as AVG()
, COUNT()
, MAX()
, MIN()
and SUM()
. Being an aggregation function, only a single row per group is returned and passed onto the next execution step.
Further Reading​
- Oracle Magazine - How to read an execution plan
- Oracle Tuning Guide - Explaining and Displaying Execution Plans
- Oracle Tuning Guide - Comparing Execution Plans Tutorial
Search online​
If this article doesn't have the information you need you can try searching online. Remember, you can contribute suggestions to this page.