Rolling Up Data in HPA Indexes 

Use

As with relational aggregates, the data consistency of the InfoCube and HPA index is based on request handling in the BI system. When you load new data packages (requests) into the InfoCube, these are not immediately available for use in a HPA index for reporting purposes. As with aggregates, the process that writes new data to the HPA index is rollup.

Integration

·        If you replace the relational aggregates in an InfoCube with a HPA index, you do not have to make further changes in the process chains or other settings. The process and the associated programs are identical.

·        The compression of data packages after rollup, as performed with aggregates to improve efficiency (see Efficiently Loading Data to Aggregates in section Setting Automatic Compression), does not apply to HPA indexes because the data on the HPA server already exists in a read-optimized format. However, it is useful to rebuild the HPA index if the InfoCube is compressed heavily after rollup (see System Response Upon Changes to Data: HPA Index in section Compression). 

·        You can use delta indexes to speed up the rollup process. For information about optimizing the performance of HPA indexes that are used particularly frequently, see Improving Efficiency Using HPA Delta Indexes.

Prerequisites

·        New data packages (requests) have been loaded into an InfoCube.

·        HPA indexes for this InfoCube have been activated and filled with data.

Features

When you rollup data for an InfoCube, the system first loads the new data into any aggregates that exist in the InfoCube, and then determines the delta of the missing records for all the tables that have an index in the HPA index of the InfoCube and indexes it. If new SIDs are generated when transaction data is loaded, the system also writes new records to the indexes of the S, X and Y tables. When the system has indexed all the indexes successfully, the data of the most recent request is released for reporting.

Activities

As with relational aggregates, you only have to exit data rollup after loading transaction data.

For more information about the different execution modes for this activity, in particular the recommended execution types Including Rollup of Data Packages As a Process in a Process Chain and Starting Rollup of Data Packages Manually see Rolling Up Data in Aggregates

In InfoCube administration, where you can see whether a rollup is missing, running or successful, the system does not differentiate between whether the InfoCube has aggregates or a HPA index.