o To use the RMU Verify command for a database, you must have
the RMU$VERIFY privilege in the root file access control
list (ACL) for the database or the OpenVMS SYSPRV or BYPASS
privilege. You must also have the SQL DBADM privilege.
o The rules that determine which qualifiers can be used in
combination on the same RMU Verify command line are as
follows:
- The Incremental, Log, Output, and Transaction_Type
qualifiers can be used in combination with any other
qualifiers on the same RMU Verify command line.
- If the All qualifier is specified, the only other
qualifiers you can specify on the same command line are:
* Noroutines (or Nofunctions)
* Nosegmented_Strings
- If the All qualifier is not specified, then any combination
of the following qualifiers can be specified on the same
command line:
* Areas
* Constraints
* [No]Functions
* Indexes
* Lareas
* [No]Root
* [No]Routines
- You must specify the Areas qualifier to specify the
Checksum_Only or Snapshots qualifier.
- You must specify the Lareas qualifier to specify the
Segmented_Strings qualifier.
- You must specify either the Areas or Lareas qualifier to
specify the Start and End qualifiers.
- You cannot specify the Indexes qualifier on the same RMU
Verify command line with the Start and End qualifiers.
- You must specify the Indexes qualifier to specify the
[No]Data qualifier.
o You can significantly improve the performance of RMU Verify
for your database by employing the verification strategies
described in the Oracle Rdb Guide to Database Maintenance. In
addition, detected asynchronous prefetch should be enabled to
achieve the best performance of this command. Beginning with
Oracle Rdb V7.0, by default, detected asynchronous prefetch
is enabled. You can determine the setting for your database by
issuing the RMU Dump command with the Header qualifier.
If detected asynchronous prefetch is disabled, and you do not
want to enable it for the database, you can enable it for your
Oracle RMU operations by defining the following logicals at
the process level:
$ DEFINE RDM$BIND_DAPF_ENABLED 1
$ DEFINE RDM$BIND_DAPF_DEPTH_BUF_CNT P1
P1 is a value between 10 and 20 percent of the user buffer
count.
o If you use the RMU Convert command with the Nocommit qualifier
to convert a database created prior to Oracle Rdb Version
6.0, and then use the RMU Convert command with the Rollback
qualifier to revert to the previous database structure level,
subsequent RMU Verify commands might produce messages such as
the following:
%RMU-W-PAGTADINV, area RDB$SYSTEM, page 1
contains incorrect time stamp
expected between 14-APR-1992 15:55:25.74
and 24-SEP-1993 13:26:06.41, found:
Beginning in Oracle Rdb Version 6.0, the fast incremental
backup feature alters the page header of updated SPAM pages to
record which page ranges have been updated since the previous
full backup operation. The RMU Verify command in versions
of Oracle Rdb prior to Version 6.0 does not contain code to
understand the updated page header and issues the PAGTADINV
warning when encountering an updated SPAM page header. The
update page headers are only detected by the RMU Verify
command and do not affect the run-time operation of Oracle
Rdb. To correct the updated SPAM pages, you can use the RMU
Repair command with the Spams qualifier as follows:
$ RMU/VERIFY/ALL/NOLOG MF_PERSONNEL
%RMU-W-PAGTADINV, area RDB$SYSTEM, page 1
contains incorrect time stamp
expected between 14-APR-1992 15:55:25.74
and 24-SEP-1993 13:26:06.41, found:
$
$ RMU/REPAIR/SPAMS MF_PERSONNEL
%RMU-I-FULBACREQ, A full backup of this database should be performed
after RMU/REPAIR
$
$ RMU/VERIFY/ALL/NOLOG MF_PERSONNEL
$
o The RMU Verify command ignores any constraint that has
been disabled (with the SQL ALTER TABLE enable-disable
clause) unless you specify the constraint name in the
Constraints=(Constraints=list) qualifier of the RMU Verify
command. If the Constraints qualifier is specified without a
list, disabled constraints are ignored.
By specifying the name of a disabled constraint in the
Constraints=(Constraints=list) qualifier, you can check it
periodically without having to reenable it. You might use
this to provide a business rule in the database that needs
checking only occasionally. This is a useful practice if the
overhead of checking the constraint during operating hours
is too expensive, or if it is already being enforced by the
application.
o The number of work files used by the RMU Verify command is
controlled by the RDMS$BIND_SORT_WORKFILES logical name. The
allowable values are 1 through 10 inclusive, with a default
value of 2. The location of these work files can be specified
with device specifications, using the SORTWORKn logical
name (where n is a number from 0 to 9). See the OpenVMS
documentation set for more information on using SORT/MERGE.
See the Oracle Rdb7 Guide to Database Performance and Tuning
for more information on using these Oracle Rdb logical names.
Because two separate sort streams are used internally by the
RMU Verify command when the Index qualifier is specified,
the number of work files specified is used for each stream.
For example, if RDM$BIND_SORT_WORKFILES is defined to be 10,
twenty work files are created.