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. |
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