REFRESH procedure

This procedure refreshes a list of snapshots.

Syntax

DBMS_SNAPSHOT.REFRESH (
   { list                 IN     VARCHAR2,
   | tab                  IN OUT DBMS_UTILITY.UNCL_ARRAY,}
   method                 IN     VARCHAR2       := NULL,
   rollback_seg           IN     VARCHAR2       := NULL,
   push_deferred_rpc      IN     BOOLEAN        := TRUE,
   refresh_after_errors   IN     BOOLEAN        := FALSE,
   purge_option           IN     BINARY_INTEGER := 1,
   parallelism            IN     BINARY_INTEGER := 0,
   heap_size              IN     BINARY_INTEGER := 0
   atomic_refresh         IN     BOOLEAN        := TRUE);

Note: This procedure is overloaded. The list and tab parameters are mutually exclusive.

Parameters

Table 8-310 REFRESH Procedure Parameters (Page 1 of 2)

Parameter	Description
list | tab	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 local 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	A string of refresh methods indicating how to refresh the listed snapshots. F or f indicates fast refresh, ? indicates force refresh, C or c indicates complete refresh, and A or a indicates always refresh, If a snapshot does not have a corresponding refresh method (that is, if more snapshots are specified than refresh methods), then that snapshot is refreshed according to its default refresh method. For example, the following EXECUTE statement within SQL*Plus: dbms_snapshot.refresh ('s_emp,s_dept,scott.s_salary','CF'); performs a complete refresh of the S_EMP snapshot, a fast refresh of the S_DEPT snapshot, and a default refresh of the SCOTT.S_SALARY snapshot.
rollback_seg	Name of the snapshot site rollback segment to use while refreshing snapshots.
push_deferred_rpc	Used by updatable snapshots only. Set this parameter to 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	If this parameter is TRUE, an updatable snapshot continues to refresh even if there are outstanding conflicts logged in the DEFERROR view for the snapshot's master table. If this parameter is TRUE and atomic_refresh is FALSE, this procedure continues to refresh other snapshots if it fails while refreshing a snapshot.
purge_option	If you are using the parallel propagation mechanism (in other words, parallelism is set to 1 or greater), 0 means do not purge, 1 means lazy purge, and 2 means aggressive purge. In most cases, lazy purge is the optimal setting. Set purge to aggressive to trim the queue if multiple master replication groups are pushed to different target sites, and updates to one or more replication groups are infrequent and infrequently pushed. If all replication groups are infrequently updated and pushed, set this parameter to 0 and occasionally execute PUSH with this parameter set to 2 to reduce the queue.
parallelism	0 means serial propagation, n > 1 means parallel propagation with n parallel server processes, and 1 means parallel propagation using only one parallel server process.
heap_size	Maximum number of transactions to be examined simultaneously for parallel propagation scheduling. Oracle automatically calculates the default setting for optimal performance. Do not set this parameter unless directed to do so by Oracle Worldwide Support.
atomic_refresh	If this parameter is set to TRUE, then the list of snapshots is refreshed in a single transaction. All of the refreshed snapshots are updated to a single point in time. If the refresh fails for any of the snapshots, none of the snapshots are updated. If this parameter is set to FALSE, then each of the snapshots is refreshed in a separate transaction. The number of job queue processes must be set to 1 or greater if this parameter is FALSE. If FALSE and the Summary Management option is not purchased, then an error is raised.