11. Maintaining Storage Structures : Modify Procedures : Options to the Modify Procedure : Allocation of Space
 
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Allocation of Space
Use the Allocation option to pre-allocate space. You can modify the table to an allocation greater than its current size to leave free space in the table. (The default is four pages if no allocation has been specified.)
Doing this allows you to avoid a failure due to lack of disk space, or to provide enough space for table expansion instead of having to perform a table extend operation. Extending a Table or Index (see page Extending a Table or Index) provides more information.
The allocated size must be in the range 4 to 8,388,607 (the maximum number of pages in a table). The specified size is rounded up, if necessary, to make sure the allocation size for a multi-location table or index is always a multiple of sixteen.
Note:  If the specified number of pages cannot be allocated, the modify procedure is aborted.
After an allocation is specified, it remains in effect and does not need to be specified again when the table or index is modified.
Example: Allocate 1000 Pages to a Table
The following example specifies that 1000 pages be allocated to table inventory:
modify inventory to btree with allocation = 10000;
In VDBA:
1. Open the Structure of Table dialog for the table.
2. Select B-tree from the Structure drop-down list.
3. Enter 1000 in the Allocation edit control.
The space allocated is 1008, due to rounding.