Sort Overflows


 
Snapshot Level
Database
Application

 
Logical Data Grouping
dbase
appl
stmt

 
Monitor Switch
Sort
Sort
Sort

Resettable

Yes

 

Event Type
Database
Connection
Statement

Logical Data Grouping
db_event
conn_event
stmt_event

 

Element Name
Element Type

sort_overflows
counter

 

Description:  The total number of sorts that ran out of sort heap and may have required disk space for temporary storage.

Usage:  At a database or application level, use this element in conjunction with "Total Sorts" to calculate the percentage of sorts that had to overflow to disk. If this percentage is high, you may want adjust the database configuration by increasing the value of sortheap.

At a statement level, use this element to identify statements that require large sorts. These statements may benefit from additional tuning to reduce the amount of sorting required.

When a sort overflows, additional overhead will be incurred because the sort will require a merge phase and can potentially require more I/O, if data needs to be written to disk.

This element provides information for one statement, one application, or all applications accessing one database.