Oracle data types

The char data type accepts strings that are of fixed length.....
BLOB, CLOB, NCLOB are stored internally where as BFILE is stored externally....
Each table in oracle has a pseudocolumn called ROWID. Oracle uses ROWID to store address of each rows of the table......
The LOB datatypes includes BLOB, CLOB, NCLOB and BFILE that can store large blocks of unstructured data such as graphic images......