QMF uses a spill file when there is no more room in virtual storage for the current data object. The spill file is a temporary storage area utilized by QMF when virtual storage is not large enough to hold the current data object.
The spill file allocation for each user should be large enough to hold all rows from the largest accessed table. If you do not allocate a spill file for a user or if you allocate a spill file that is too small, problems can occur. QMF can encounter an insufficient storage condition which can degrade response time.
The Spill File online facility helps to ensure the correct allocation for a user's spill file. By entering the name of a table and the type of device on which the spill file will reside, the allocation will be calculated automatically.