How Tags are used in Streams

For example, the following procedure can be used to set the tag to the hexadecimal value of 2A in the current session:

BEGIN
DBMS_STREAMS.SET_TAG(tag => HEXTORAW('2A')  );
END;
/

After running this procedure, each redo entry generated by DML or DDL statements in the current session will have a tag value of 2A. Running this procedure affects only the current session.

The tag for all redo entries generated by the current session can be retrieved by using the get_tag procedure in the dbms_streams package. For example, to get the hexadecimal value of the tags generated in the redo entries for the current session, use the following SQL block:

SET SERVEROUTPUT ON
DECLARE
raw_tag RAW(2000);
BEGIN
raw_tag := DBMS_STREAMS.GET_TAG();
DBMS_OUTPUT.PUT_LINE('Session Tag Value = ' ||  RAWTOHEX(raw_tag));
END;
/