o Refer to the Oracle Rdb7 Guide to Database Performance and
Tuning for complete information about the RMU Show Statistics
command, including information about using formatted binary
output files from the RMU Show Statistics command.
o To use the RMU Show Statistics command for a database, you
must have the RMU$SHOW privilege in the root file ACL for the
database or the OpenVMS SYSPRV, BYPASS, or WORLD privilege.
To use the RMU Show Statistics command to display statistics
about other users, you must have the OpenVMS WORLD privilege.
To use the RMU Show Statistics command to update fields in
the Database Dashboard (specified with the Options=Update
qualifier), you must have both the OpenVMS WORLD and BYPASS
privileges.
o If a database recovery process is underway, you cannot
exit the Performance Monitor using Ctrl/Z or "E" from the
interactive display menu. You must use Ctrl/Y or wait for the
recovery process to complete. Exiting from the Performance
Monitor causes Oracle RMU to request several locks; however,
these locks cannot be granted because the recovery process
stalls all new lock requests until the recovery is complete.
o Since Oracle Rdb V4.1, a number of changes have been made to
the data structures used for the RMU Show Statistics command.
If you are having a problem with an application that accesses
the RMU Show Statistics field structures, recompile your
application with SYS$LIBRARY:RMU$SHOW_STATISTICS.CDO (or
RMU$SHOW_STATISTICSnn.CDO in a multiversion environment, where
nn is the version of Oracle Rdb you are using).
o The Oracle Rdb RMU Show Statistics command displays process
CPU times in excess of 1 day. Because the width of the CPU
time display is limited, the following CPU time display
formats are used:
- For CPU time values less than 1 day: "HH:MM:SS.CC"
- For CPU time values less than 100 days but more than 1 day:
"DD HH:MM"
- For CPU time values more than 100 days: "DDD HH:MM"
o The following caveats apply to the Cluster Statistics
Collection and Presentation feature:
- Up to 95 cluster nodes can be specified. However, use
cluster statistics collection prudently, as the system
overhead in collecting the remote statistics may be
substantial depending on the amount of information being
transmitted on the network.
- Cluster statistics are collected at the specified display
refresh rate. Therefore, set the display refresh rate to
a reasonable rate based on the number of cluster nodes
being collected. The default refresh rate of 3 seconds is
reasonable for most remote collection loads.
- If you specify the Cluster qualifier, the list of cluster
nodes applies to any database accessed during the Show
Statistics session. When you access additional databases
using the Switch Database option, the same cluster nodes
are automatically accessed. However, any nodes that you
added manually using the Cluster Statistics menu are
not automatically added to the new database's remote
collection.
In other words, manually adding and deleting cluster nodes
affects only the current database and does not apply to
any other database that you may have accessed during the
session. For example, when you run the Show Statistics
utility on node ALPHA3 with manually added node BONZAI,
subsequently switching to BONZAI as the current node will
not display cluster statistics from node ALPHA3 unless you
manually add that node. Furthermore, switching back to node
ALPHA3 as the current node loses the previous collection of
node BONZAI because it was manually added.
- Both DECnet and TCP/IP network protocols are supported.
By default, the DECnet protocol is used. To explicitly
specify which network protocol to use, define the RDM$BIND_
STT_NETWORK_TRANSPORT to DECNET or TCPIP respectively. The
RDM$BIND_STT_NETWORK_TRANSPORT logical name must be defined
to the same definition on both the local and cluster nodes.
The RDM$BIND_STT_NETWORK_TRANSPORT logical name can be
specified in LNM$FILE_DEV on the local node but must be
specified in the LNM$SYSTEM_TABLE on all remote nodes.
NOTE
There is no command qualifier to specify the network
protocol.
- The Output qualifier continues to work as usual, but when
in cluster mode writes the cluster statistics information
to the binary output file.
- The Cluster qualifier cannot be specified with the Input
qualifier. Furthermore, the online selection of cluster
nodes is not available when you use the Input qualifier.
- While the collection and presentation feature is active,
all on-screen menu options continue to operate as usual.
This includes the time-plot, scatter-plot, screen pause,
and various other options.
- There is no way to exclude the current node from statistics
collection. Log in to another node if you want to do this.
- The cluster collection of per-process stall information
automatically detects the binding or unbinding of processes
to cluster databases. There is no need to manually refresh
the database information on the current node.
- If the database is not currently open on the specified
node, Oracle RMU still attempts to collect cluster
statistics. However, you must open the remote database
prior to regular process attaches.
- When you display any of the per-process screens that
support cluster statistics collection, such as the Stall
Messages screen, you can zoom in on any of the displayed
processes to show which node that process is using.
- Using the Cluster Statistics submenu from the Tools menu,
it is also possible to collect statistics from all open
database nodes using the Collect From Open Database Nodes
menu option. This option simplifies the DBA's job of
remembering where the database is currently open. However,
subsequently opened nodes are not automatically added to
the collection; these must be manually added.
- The cluster statistics collection is an intracluster
feature in that it works only on the same database, using
the same device and directory specification used to run the
initial RMU Show Statistics command (that is, on a shared
disk). The cluster statistics collection does not work
across clusters (intercluster).
- When you replay a binary output file, the screen header
region accurately reflects the number of cluster nodes
whose statistics are represented in the output file.