LOB in Oracle
In Oracle, a LOB is simply a pointer that points to an index that is stored in a LOBINDEX segment. The index points to the chunks that make up the LOB that are stored in LOBSEGMENT segment.
Binary large object (BLOB): For unstructured binary data
--EMPTY_BLOB and EMPTY_CLOB return an empty LOB locator that can be used to initialize a LOB variable
blob := empty_blob();
-- From Varchar
blob := TO_BLOB(UTL_RAW.CAST_TO_RAW('abc'));
Character large object (CLOB): For character data
-- EMPTY_BLOB and EMPTY_CLOB return an empty LOB locator that can be used to initialize a LOB variable
clob := empty_clob();
-- To_clob
clob := to_clob('abc');