Sorter start sort external

Number of external sorts started.

High values indicate excessive use of the external sorter.

The external sorter is invoked when space required for the sort exceeds the memory available for the internal sorter. Because the external sorter spills to disk, excessive use of it negatively affects performance. Consider increasing the sort array size configuration parameter to avoid the external sorter being invoked.

Sorter add row external

Number of rows added to external sorter.

If the Sorter add row external counter is incrementing faster than the Sorter fetch row external counter, the external sorter is congested. For more details, see Sorter fetch row external.

Sorter fetch row external

Number of rows read from external sorter.

After a row is fetched, the memory is released. If the Sorter add row external counter is incrementing faster than the Sorter fetch row external counter, the external sorter might be congested, which can lead to unsatisfactory query performance. Consider increasing the memory that is used by the internal sorter by increasing the value of the SQL.SortArraySize parameter. Also consider reducing the number of sorts that are performed in the application.

If external sorting is still required, try to speed up the external sorter by ensuring the underlying disk is as fast as possible. For example, use a solid-state drive (SSD) or a RAM drive.

Sorter open file external

Number of files opened/sec in external sorter

Sorter activecnt external

Number of currently active external sorts

Sorter waitcnt external

Number of external sort requests waiting to be started

Sorter wait external

Number of external sort requests wait/sec

Sorter filecnt external

Number of temporary files currently used for external sorting

Sorter memblockcnt external

Number of memory blocks currently used for external sorting

Sorter failed external

Number of times external sort has failed to start

Sorter start sort internal

Number of internal sorts started/sec

Sorter add row internal

Number of rows added to internal sorter/sec

Sorter fetch row internal

Number of rows read from internal sorter/sec