lets you add an overflow data segment to the specified index-organized table.You can also use this clause to explicitly allocate an extent to or deallocate unused space from an existing overflow segment.To enable a unique or primary key constraint, you must have the privileges necessary to create an index on the table.You need these privileges because Oracle Database creates an index on the columns of the unique or primary key in the schema containing the table.Oracle recommends that a representative set of data already exist in the table before you specify This clause lets you change a table that is not index organized into an index-organized table.Index-organized tables keep data sorted on the primary key and are therefore best suited for primary-key-based access and manipulation.
If an overflow segment is needed but you have not specified You can add an overflow data segment to each partition of a partitioned index-organized table.
Further, if your application has any rowid-based triggers, you should disable them before issuing this clause.
, then Oracle Database only defragments the segment space and compacts the table rows for subsequent release.
You can add LOB columns to nonpartitioned and partitioned tables.
You can specify LOB storage at the table and at the partition or subpartition level.