Follow these guidelines to
optimize use of the Dataset Attribute
Database feature:
- In a multi-system, shared hard-disk-drive
environment, only enable
Dataset Attribute collection on one of the connected systems, ideally
a non-production system. This approach avoids collection of the same
data set space information on multiple systems, and places the work
for collection on the most lightly loaded system.
- Use product-provided
queries and workspaces rather than user-created,
as they have been crafted and tuned for maximum performance. User-defined
queries can incur significant overhead if a very large number of data
sets needs to be examined to resolve the predicates.
- User-created
situations written against the Dataset Detail table
run against the complete data set database. Do not set a Situation
Sampling Interval smaller than the Dataset Attribute Database collection
cycle, because attributes in the database are not updated more often
than that.
- In Tivoli OMEGAMON XE for Storage
version 4.2.0
Interim Feature 2.0, you can define a dataset attribute group to logically
group a related set of data sets. When you craft a group, define the
properties and attributes such that they limit the number of data
sets that make up the group. If a large number of data sets in the
Dataset Attribute Database match the criteria for your group, or a
large number of data sets must to be examined to determine whether
they match the criteria, this activity can require excessive processing,
network and space resources.
- VSAM data sets are typically
reported under their cluster name
in the Dataset Attribute Database workspaces. Although the data sets
contain a cluster component, a data component and an index component,
these components are counted as a single data set in the Dataset Attribute
Database workspaces. In addition, only the cluster component name
displays in the table views to represent the data set. In counters
displaying the "Total Datasets" in a group, a single VSAM data set
is counted only once. Note that after a VSAM data set has been migrated,
the cluster, data and index components are treated as individual data
sets by the Dataset Attribute Database workspaces. Each component
appears on a separate line in table views. In counters displaying
the "Total Datasets" in a group, each component is counted separately,
increasing the data set count (in contrast to the count prior to migration).
This discrepancy occurs because the catalog entry for a VSAM dataset
is changed after the data set is migrated. The catalog entry change
causes an inaccurate count. In fact, the Catalog Search Index reports
these component names as type 'A' (Non-VSAM data sets).