# Configuring the Dataset Attribute Database feature

The Dataset Attributes Database feature is turned off by default. It is recommended that you first run a collection on a subset of volumes to test how the feature affects performance. Use the information from this test session to estimate the impact of collection on the address space of the Tivoli® Enterprise Monitoring Server and on the overall z/OS® system. This estimate can help you choose optimal configuration settings, such as, the volumes and storage groups to exclude from collection, what time of day to start collection of data and what deadline (if any) to impose for completion of collection.

You use this dialog box to Use the Dataset Attribute Collection Control dialog box to configure data collection for the Dataset Attribute Database feature. Right-click in a row of the Dataset Attribute Summary workspace and select Dataset Attribute Collection Control to launch the dialog box.

Table 1. Dataset Attribute Data Collection dialog box
Section in the dialog box | Comments
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Data Collection settings:
Start data collection at (hh:mm) | When you select this check box, most of the other fields in the dialog box become active for you to configure. hh is an integer from 1 to 12 and mm is an integer from 0 to 60.
Stop data collection at (hh:mm) | Use this setting to prevent data collection from continuing into a time period when critical jobs run that require significant amounts of system resources. hh is an integer from 1 to 12 and mm is an integer from 0 to 60. If you specify a stop time and collection is halted because that time is reached, attributes and reports for every data set processed up to the point that collection was halted are available for viewing from the Tivoli Enterprise Portal.
Collect catalog data | When you deselect this check box no catalog information is obtained for any data set. Note: By deselecting this option, you reduce resource consumption and elapsed time. However, several summary reports are empty when you do not collect this data, for example, CA/CI Split Summaries and Catalog/Uncataloged Summaries.
Number of data rows to collect for Top N reports | The default is 20 rows. The range is 1 to 100 rows. Many of the reports for the Dataset Attribute Database feature involve Top N data. You can lower or raise this setting to adjust the amount of impact that this feature has on system resources versus the number of rows returned in each Summary report. For data sets that have the same key value as the smallest key in the table (for example, lowest number of allocated tracks in the Top N Space Allocated table), the first data set encountered with that value is the one that is displayed in the report. Defaults for Top N data collection are as follows: An inefficient block size is defined as `blksize < 128`. A mature data set is defined as `days since last reference > 366`.
Exclusions:
Volumes Storage Groups | You can specify VOLSER or storage group names to exclude volumes from data collection. A volume that matches either exclusion specifications is excluded. You can specify up to 32 exclusions of each type. You can specify a partial name pattern and place the wildcard character (*) at the end. Volumes and Storage Groups whose names match the pattern are excluded.
Data Collection Status:
Status message Force Start button or Force Stop button | Status messages include, Collection not active, Collection in progress, Collection waiting, Collection failed, Collection halted due to deadline, and Collection halted by user or operator. Click Force Start to manually force data collection to start. A Force Stop button is available while data collection is running to manually force data collection to stop. Results are displayed, including all data sets processed up to the point that collection was halted.