Oracle Distributed Systems

Name

DBMS_REPCAT.SEND_AND_COMPARE_OLD_VALUES (Oracle8 Only)

Synopsis

The default behavior of advanced replication is to send the old and new values of every column to participating master sites whenever you update a row in a replicated table. At the destination sites, Oracle uses this information to ensure that the version of the row that you updated matches the version of the row currently at the destination. However, if you know that certain columns in a table will never change, you can avoid sending the data in these columns when you propagate updates to participating master sites. Using the SEND_AND_COMPARE_OLD_VALUES procedure (available only in Oracle8) in this way, you’ll reduce propagation overhead.

PROCEDURE DBMS_REPCAT.SEND_AND_COMPARE_OLD_VALUES
   (sname IN VARCHAR2
    oname IN VARCHAR2,
    {column_list IN VARCHAR2 | column_table IN dbms_repcat.varchar2s},
    operation IN VARCHAR2 := 'UPDATE',
    send IN BOOLEAN := TRUE);

The configuration changes you specify with this procedure do not take effect unless the min_communication parameter is TRUE for the table in question. That is, you must have executed GENERATE_REPLICATION_SUPPORT for the table with min_communication = TRUE.

If you change the propagation mode in Oracle8, you must also regenerate the SEND_AND_COMPARE_OLD_VALUES procedure.

Parameters

Parameter Name	Description
sname	Name of the replication group whose propagation mode is being altered.
oname	Table being altered.
column_list	Comma-separated list of columns whose propagation mode is ...