• When extending a table, not only the physical extension must be performed, but the extension must also be recorded. Therefore, avoid an excessively small extend size that requires many additional small extensions.

• In an environment that is short of disk space, a large extend size can cause an operation to fail, even when there is sufficient disk space for the particular operation.

• Windows: On a file system that requires the underlying files to be written to when allocating disk space, a large extend size can be undesirable because it affects the performance of the operation that causes the extension.

• UNIX: On a file system that requires the underlying files to be written to when allocating disk space, a large extend size can be undesirable because it affects the performance of the operation that causes the extension.

• VMS: On file systems that provide calls for allocating disk space, a large extend size helps reduce the amount of table fragmentation.