WRITE

The WRITE procedure writes a specified amount of data to an internal LOB (starting from an absolute offset that begins with LOB).

The data is written from the buffer parameter. WRITE replaces (overwrites) any existing data at the specified LOB offset with the specified length.

Syntax

DBMS_LOB.WRITE (
lob_loc  IN OUT  NOCOPY BLOB,
amount   IN             INTEGER,
offset   IN             INTEGER,
buffer   IN             RAW);

DBMS_LOB.WRITE (
lob_loc  IN OUT  NOCOPY CLOB CHARACTER SET ANY_CS,
amount   IN             INTEGER,
offset   IN             INTEGER,
buffer   IN             VARCHAR2 CHARACTER SET ANY_CS);

Parameters

Exceptions

Considerations

• An error occurs if the input size exceeds the buffer data. If the input size is less than the buffer data, only the number of bytes or characters in the buffer is written to the LOB. If the specified offset exceeds the end of the current data in the LOB, zero-byte fillers or spaces are inserted into the BLOB or CLOB.

• The VARCHAR2 buffer must match the format of the CLOB parameter. In other words, if the input LOB parameter is of type CLOB, the buffer must contain CHAR data.

• When you call DBMS_LOB.WRITE from a client, the buffer must contain data in the client character set. Before writing the buffer data to the LOB, the database converts the client buffer to the server's character set.

• Wrapping LOB operations in the Open/Close interface is not mandatory. If the LOB is not opened before the operation, the functional index and domain index on the LOB column are updated during the call. If the LOB is opened before the operation, it must be closed before the transaction is committed. When the internal LOB is closed, the functional index and domain index on the LOB column are updated.

• If the LOB operation is not wrapped in the Open/Close interface, the functional index and domain index are updated each time the LOB is written. To avoid performance issues, we recommend that you include LOB write operations in OPEN or CLOSE statements.

• Unless the write operation is specified to overwrite the entire LOB, WRITE obtains the LOB before writing to it.