OCILobTrim()

Purpose

Trims/truncates the LOB value to a shorter length.

Syntax

sword OCILobTrim ( OCISvcCtx       *svchp,
                   OCIError        *errhp,
                   OCILobLocator   *locp,
                   ub4             newlen );

Parameters

svchp (IN)

The service context handle.

errhp (IN/OUT)

An error handle you can pass to OCIErrorGet() for diagnostic information in the event of an error.

locp (IN/OUT)

An internal LOB locator that uniquely references the LOB. This locator must be a locator that was obtained from the server specified by svchp.

newlen (IN)

The new length of the LOB value, which must be less than or equal to the current length. For character LOBs, it is the number of characters, for binary LOBs and BFILEs it is the number of bytes in the LOB.

Comments

This function trims the LOB data to a specified shorter length. The function returns an error if newlen is greater than the current LOB length. This function is valid only for internal LOBs. FILEs are not allowed.

It is not mandatory that you wrap this LOB operation inside the Open/Close calls. If you did not open the LOB prior to performing this operation, then the functional and domain indexes on the LOB column are updated during this call. However, if you did open the LOB prior to performing this operation, then you must close it before you commit or rollback your transaction. When an internal LOB is closed, it updates the functional and domain indexes on the LOB column.

If you do not wrap your LOB operations inside the Open/Close API, then the functional and domain indexes are updated each time you write to the LOB. This can adversely affect performance. If you have functional or domain indexes, we recommend that you enclose write operations to the LOB within the open/close statements.

Related Functions

OCIErrorGet(), OCILobRead(), OCILobAppend(), OCILobCopy(), OCILobErase(), OCILobWrite(), OCILobWriteAppend()