Oracle7 Server Administrator's Guide
Manually Allocating Storage for a Table
Oracle dynamically allocates additional extents for the data segment of a table, as required. However, you might want to allocate an additional extent for a table explicitly. For example, when using the Oracle Parallel Server, an extent of a table can be allocated explicitly for a specific instance.
A new extent can be allocated for a table using the SQL command ALTER TABLE with the ALLOCATE EXTENT option.
See Also: For information about the ALLOCATE EXTENT option, see the Oracle7 Parallel Server Concepts & Administration guide.