You should consider setting this environment variable if the total size of files in your SORT operation is over 1GB.
During a SORT operation, non-key data portions of a record are held in memory depending on the size of SORTSPACE:
|Size of SORTSPACE||Maximum non-key data portion held in memory|
|1MB or greater||5KB|
|4MB or greater||12KB|
|8MB or greater||28KB|
|16MB or greater||62KB|
The default value is 0.