LONG columns can be up to 2 gigabytes in length. In importing and exporting, the
LONG columns must fit into memory with the rest of each row's data. The memory used to store
LONG columns, however, does not need to be contiguous, because
LONG data is loaded in sections.
Import can be used to convert
LONG columns to
CLOB columns. To do this, first create a table specifying the new
CLOB column. When Import is run, the
LONG data is converted to
CLOB format. The same technique can be used to convert
RAW columns to
Oracle recommends that you convert existing
LONG columns to LOB columns. LOB columns are subject to far fewer restrictions than
LONG columns. Further, LOB functionality is enhanced in every release, whereas
LONG functionality has been static for several releases.