RDF System Management Manual

Subvolume- and File-Level Replication
HP NonStop RDF System Management Manual—524388-003
11-3
INCLUDE and EXCLUDE Processing
INCLUDE and EXCLUDE Processing
You can specify a maximum of 100 INCLUDE and EXCLUDE parameters for each
volume, in any combination. When you specify both INCLUDE and EXCLUDE clauses
for a given volume, the clauses are processed hierarchically, with the INCLUDE
clauses processed first and EXCLUDE clauses processed second.
Error Checking
Extensive checking is done when the subvolume and file names are parsed, and
invalid names cause errors. The logic of a series of INCLUDE and EXCLUDE
clauses, however, is not checked. For example, the following is not regarded as an
error, even though it makes no sense because everything will be filtered out:
SET VOLUME INCLUDE MMTEST10.*
SET VOLUME EXCLUDE MMTEST10.*
Performance Ramifications
The extractor processes all INCLUDE and EXCLUDE clauses. If the extractor reads an
audit record associated with a file or table not specified in an INCLUDE clause, it
discards the record. Similarly, if the extractor reads an audit record associated with a
file or table specified in an EXCLUDE clause, it discards the record.
With volume-level replication, the extractor needs to test only the volume name to
determine if a record should be sent to the backup system. With subvolume- and file-
level replication, however, the extractor must also test the subvolume name and
filename. Hence there is more work to do with subvolume- and file-level replication.
Note that if you use large numbers of INCLUDE and EXCLUDE clauses for each
volume, the extractor may have to evaluate the subvolume name and filename against
multiple lists, which could lead to increased CPU usage by the extractor and lower
extractor performance than with simple volume-level replication. Therefore, you should
be careful about how many INCLUDE and EXCLUDE clauses you specify for each
volume. The use of wildcard characters in subvolume names and filenames can help
considerably. For example, to replicate all of the files within all subvolumes whose
names begin with the letters DB, you can do so with a single INCLUDE clause, as
follows:
INCLUDE DB*.*
Note. When you are adding multiple volumes using INCLUDE and EXCLUDE lists, you must
be sure to issue a RESET VOLUME command after each ADD VOLUME command or the
previous INCLUDE/EXCLUDE lists will carry forward to the next volume being added.