Spotlight on Oracle 10.10

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The following table shows some of the aggregation operations you may encounter while using the Explain SQL window.

Operation	Option	Description
COUNT		Count the rows in the result set in order to satisfy the COUNT() function.
COUNT	STOPKEY	Count the number of rows returned by a result set, and stop processing when a certain number of rows are reached. This is usually the result of a WHERE clause which specifies a maximum ROWNUM (for instance WHERE ROWNUM <= 10).
SORT	AGGREGATE	This occurs when a group function is used on data that is already grouped. For instance, select MAX(AVG(SALARY)) from EMPLOYEES GROUP by MANAGER_ID.
SORT	JOIN	Sort the rows in preparation for a merge join.
SORT	UNIQUE	A sort to eliminate duplicate rows. Typically occurs as a result of using the distinct clause.
PARTITION	SINGLE	Denotes that operations were performed on a single partition.
PARTITION	CONCATENATED	Denotes that operations were performed on multiple partitions.
LOAD	AS SELECT	Denotes an insert append operation.
SORT	GROUP BY	A sort of a result set in order to group them for the GROUP BY CLAUSE.

Spotlight on Oracle 10.10 - Release Notes