RMAN incremental backups

You can use proxy copy backups as a part of the incremental strategy with conventional non-proxy RMAN backups. RMAN lets you create a proxy copy incremental level 0 backup. This backup can be the base for subsequent RMAN traditional incremental backups (level 1-n). To accomplish this backup, perform a snapshot proxy copy (file-based) level 0 incremental backup and follow with an RMAN traditional (stream-based) level 1-n incremental backup.

In Oracle 10g it is possible to track changed blocks using a change tracking file. Enabling change tracking does produce a small amount of database overhead, but it greatly improves the performance of incremental backups. Use the ALTER DATABASE ENABLE BLOCK CHANGE TRACKING; sqlplus command to enable block change tracking on the database.

In the following example, the first run command initiates a proxy copy backup of tablespace tbs1. NetBackup for Oracle uses a snapshot file-based backup to perform a full tablespace backup. RMAN designates this backup as eligible for incremental level 1-n backups. The second run command initiates a traditional non-proxy level 1 incremental backup of the same tablespace tbs1. In this case, NetBackup for Oracle performs a stream-based backup.

run {
allocate channel t1 type 'SBT_TAPE';
backup 
    incremental level 0
    proxy
    format 'bk_%U_%t'
    tablespace tbs1;
release channel t1;
}
  
run {
allocate channel t1 type 'SBT_TAPE';
backup 
    incremental level 1
    format 'bk_%U_%t'
    tablespace tbs1;
release channel t1;
}