Oracle7 Server Distributed Systems Volume II: Replicated Data

DBMS_SNAPSHOT.REFRESH

Purpose

To consistently refresh one or more snapshots that are not members of the same refresh group. For additional information, refer to

Syntax

The parameters for the REFRESH procedure are described in Table 12 - 188. The syntax for this procedure is shown below:

DBMS_SNAPSHOT.REFRESH(
		list 			IN	VARCHAR2,
		method 		IN	VARCHAR2 DEFAULT NULL,
		rollback_seg		IN	VARCHAR2 DEFAULT NULL,
		push_deferred_rpc 	IN	BOOLEAN DEFAULT TRUE,
		refresh_after_errors	IN	BOOLEAN DEFAULT FALSE)

parameter description
list Comma-separated list of snapshots that you want to refresh. (Synonyms are not supported.) These snapshots can be located in different schemas and have different master tables; however, all of the listed snapshots must be in your current database. Alternatively, you may pass in a PL/SQL table of type DBMS_UTILITY.UNCL_ARRAY, where each element is the name of a snapshot.
method Type of refresh to perform for each snapshot listed; `F' or `f' indicates a fast refresh, `C' or `c' indicates a complete refresh, and `?' indicates a default refresh. If you specified a refresh mode when you created the snapshot, that mode is used when you specify a default refresh. If no mode was specified, Oracle performs a fast refresh if possible; otherwise, it performs a complete refresh. If the METHOD list contains fewer elements than the snapshot LIST, the trailing elements in the snapshot list are refreshed using a default refresh. For example, the following EXECUTE statement within SQL*Plus:
EXECUTE dbms_snapshot.refresh('emp, dept, scott.salary', 'CF');
performs a complete refresh of the EMP snapshot, a fast refresh of the DEPT snapshot, and a default refresh of the SCOTT.SALARY snapshot.
rollback_seg Name of the snapshot site rollback segment to use while refreshing snapshots.
When you call REFRESH, all of the listed snapshots are updated to a single point in time. If the refresh fails for any of the snapshots, none of the snapshots are updated.
push_deferred_rpc Used by updatable snapshots only. Use the default value, TRUE, if you want to push changes from the snapshot to its associated master before refreshing the snapshot. Otherwise, these changes may appear to be temporarily lost.
refresh_after_errors Used by updatable snapshots only. Set this parameter to TRUE if you want the refresh to proceed even if there are outstanding conflicts logged in the DefError view for the snapshot's master.

Table 12 - 188. Parameters for DBMS_SNAPSHOT.REFRESH

parameter	description
`list`	Comma-separated list of snapshots that you want to refresh. (Synonyms are not supported.) These snapshots can be located in different schemas and have different master tables; however, all of the listed snapshots must be in your current database. Alternatively, you may pass in a PL/SQL table of type DBMS_UTILITY.UNCL_ARRAY, where each element is the name of a snapshot.
`method`	Type of refresh to perform for each snapshot listed; `F' or `f' indicates a fast refresh, `C' or `c' indicates a complete refresh, and `?' indicates a default refresh. If you specified a refresh mode when you created the snapshot, that mode is used when you specify a default refresh. If no mode was specified, Oracle performs a fast refresh if possible; otherwise, it performs a complete refresh. If the METHOD list contains fewer elements than the snapshot LIST, the trailing elements in the snapshot list are refreshed using a default refresh. For example, the following EXECUTE statement within SQL*Plus: `EXECUTE dbms_snapshot.refresh('emp, dept, scott.salary', 'CF');` performs a complete refresh of the EMP snapshot, a fast refresh of the DEPT snapshot, and a default refresh of the SCOTT.SALARY snapshot.
`rollback_seg`	Name of the snapshot site rollback segment to use while refreshing snapshots. When you call REFRESH, all of the listed snapshots are updated to a single point in time. If the refresh fails for any of the snapshots, none of the snapshots are updated.
`push_deferred_rpc`	Used by updatable snapshots only. Use the default value, TRUE, if you want to push changes from the snapshot to its associated master before refreshing the snapshot. Otherwise, these changes may appear to be temporarily lost.
`refresh_after_errors`	Used by updatable snapshots only. Set this parameter to TRUE if you want the refresh to proceed even if there are outstanding conflicts logged in the DefError view for the snapshot's master.