How Db2 unloads data

Db2 unloads data by table space scan with sort, table space scan, or clustering index.

Db2 unloads data by one of three methods:

Table space scan with sort: If at least one table space has an index, Db2 uses a table space scan with a sort.
Table space scan: Db2 uses a table space scan for simple table spaces that contain more than one table, or that contain one table but do not have an index.
Clustering index: Db2 uses this option for simple table spaces that contain one table and have an index, and for tables in a segmented (non-UTS) table space that have an index.