REPORT (Generate Reports) › TYPE=DATANE - Native Sequence Efficiency Report

TYPE=DATANE - Native Sequence Efficiency Report

A DBUTLTY DATANE report provides a detailed native sequence efficiency report for the selected data table. The DATANE report provides detailed insight into the physical order of the data rows in comparison to the order of the Native (sequence) Key.

The information provided by the report is one of the key factors when considering whether a data table is a good candidate for reorganization. The CA Datacom/DB Data Reorganization Green Book provides a detailed best-practice process that includes these key information points:

• Native Efficiency Report (DATANE)
• Sequential accesses by the Native Key
• Sequential accesses by the non-Native Key
• Sequential accesses as a portion of the total table accesses.

The DATANE report uses a highly efficient index level process that has minimal effect on MUF processing. However, the DATANE function reads through the index for the table using one key and can do some limited data row retrievals. The DATANE report must be executed while the MUF is active and the database table is available at the least for read processing.

The DATANE report can process information while the table is open for update by other users. Update tasks in the MUF that add, delete, or move data rows affect the accuracy of the DATANE report. We recommend that the DATANE report is executed when there is a minimal amount of update activity against the selected data table. The DATANE report cannot be executed against a table that is locked for single-user processes such as a DBUTLTY LOAD.

The DATANE report builds a simple report that shows the detailed data row sequential efficiency for a selected data table. The report can help you determine whether to reorganize the table.

In most cases, run the DATANE using the Native Key. You can also use a key other than the Native Key. This ability allows you to compare the data row efficiency with various keys. In some cases, you want to see if a different key would better match the data row order. In other cases, you have several keys that are similar to the Native Key and you want to measure the efficiency of those keys.

Before the DATANE report, most users relied on various sources of information to determine whether to reorganize the table. The sources were the number of overflows in the data area, batch job run times, and so on. In most cases, this information was limited in its effectiveness.