Replication Management API Reference, 173 of 179

PURGE_LOG procedure

This procedure purges rows from the snapshot log.

Syntax

DBMS_SNAPSHOT.PURGE_LOG (
   master        IN   VARCHAR2,
   num           IN   BINARY_INTEGER := 1,
   flag          IN   VARCHAR2       := 'NOP');

Parameters

Table 8-308 PURGE_LOG Procedure Parameters

Parameter Description

Parameter	Description
master	Name of the master table.
num	Number of least recently refreshed snapshots whose rows you want to remove from snapshot log. For example, the following statement deletes rows needed to refresh the two least recently refreshed snapshots: `dbms_snapshot.purge_log('master_table', 2);` To delete all rows in the snapshot log, indicate a high number of snapshots to disregard, as in this example: `dbms_snapshot.purge_log('master_table',9999);` This statement completely purges the snapshot log that corresponds to `MASTER_TABLE` if fewer than 9999 snapshots are based on `MASTER_TABLE`. A simple snapshot whose rows have been purged from the snapshot log must be completely refreshed the next time it is refreshed.
flag	Specify `DELETE` to guarantee that rows are deleted from the snapshot log for at least one snapshot. This argument can override the setting for the argument `num`. For example, the following statement deletes rows from the least recently refreshed snapshot that actually has dependent rows in the snapshot log: `dbms_snapshot.purge_log('master_table',1,'DELETE');`

master

Name of the master table.

num

Number of least recently refreshed snapshots whose rows you want to remove from snapshot log. For example, the following statement deletes rows needed to refresh the two least recently refreshed snapshots:

dbms_snapshot.purge_log('master_table', 2);

To delete all rows in the snapshot log, indicate a high number of snapshots to disregard, as in this example:

dbms_snapshot.purge_log('master_table',9999);

This statement completely purges the snapshot log that corresponds to MASTER_TABLE if fewer than 9999 snapshots are based on MASTER_TABLE. A simple snapshot whose rows have been purged from the snapshot log must be completely refreshed the next time it is refreshed.

flag

Specify DELETE to guarantee that rows are deleted from the snapshot log for at least one snapshot. This argument can override the setting for the argument num. For example, the following statement deletes rows from the least recently refreshed snapshot that actually has dependent rows in the snapshot log:

dbms_snapshot.purge_log('master_table',1,'DELETE');