The summary information is the only portion of this report that is not optional. It contains all of the statistics applicable to the data set as a whole. We will now examine each of the fields on this report.
The total number of data records in the data set. This can or cannot have the same value as the total records value in the catalog section of this report. Remember that the total records value printed in the catalog section is based on the value maintained in the catalog while the number in this section is based on the actual records in the cluster. This value is therefore more accurate.
This is the total number of bytes or characters of data that are used to hold the data records in the cluster.
The percent used gives an indication of the space already consumed in the data component. It accounts for space used to hold data records, control information overhead, and any dead space encountered in the data set.
This field gives the number of control intervals in the data component that contain data records.
This is the number of control intervals in the data component that are marked as free by the sequence set in the index. Because these control intervals are marked as free, CA Disk does not attempt to read them.
This is the number of control intervals that do not contain any data records but that are not marked as free in the index. The significance of this is that the control interval does have a compressed key pointing to it from the index, and therefore can only be used by records that have keys that fall into the range of the control interval. This condition can occur in some database management systems, such as IMS or CICS, when the DFP control interval reclamation facility is disabled. This number can be an indication of wasted space in a cluster, particularly in files that have their primary activity occur randomly throughout the cluster. If this number becomes significantly large in a data set, reorganization can be in order so that the unused control intervals can be reclaimed.
This value is the percentage of control intervals allocated to the data component that contain at least one data record.
The remaining portion of this print line has several estimated values listed. These values are based upon the data found in the cluster and assume that the same data characteristics will apply to future records added to the data set.
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