1. Oracle Enterprise Performance Management Cloud Operations Guide
  2. Understanding the EPM Cloud Troubleshooting Process
  3. Understanding Implicit and Explicit BSO Restructures

Understanding Implicit and Explicit BSO Restructures

Each Oracle Hyperion Planning cube has two Oracle Essbase parts: metadata (dimensions, members, structures, hierarchies that are stored in Essbase outline) and data (which includes data stored in blocks consisting of a combination of dense members and index to the blocks, where a new block is created for every sparse dimension). These parts may be altered by a Planning database refresh or an Essbase BSO restructure.

Database Refresh or Implicit Restructures

Member or hierarchy changes made to Planning dimensions, members, or member properties are pushed to Essbase during a database refresh. A database refresh implicitly triggers a restructure in Essbase but does not remove #missing blocks. Database refresh is executed for all Planning cubes. Implicit restructures can result in the following types of restructures:

  • Outline only: Always happens on all restructure requests.
  • Index only: This is a low impact restructure and is used to restructure index, for example, after you add or move a new sparse member, or after you rename the alias of a sparse member.
  • Index and block: This high impact restructure involves the restructuring of the data within the database, for example, after you add, delete, or move a dense member. It involves the restructuring of index files that hold the sparse index references and page files that hold dense blocks.

    If the Essbase cube contains no data, index and page files are not present. In such cases, only the outline is restructured.

Explicit Restructure

You trigger an explicit restructure for a specific Essbase cube through a job, or by using Oracle Hyperion Calculation Manager, EPM Automate or REST APIs.

An explicit restructure does not push changes from Planning to Essbase. It always rewrites the metadata and data (outline, index, and page files), regardless of changes. It also removes #missing blocks and blocks tagged for deletion by a CLEARBLOCK calculation script.

Explicit restructures always execute high impact restructures involving rewrite of the data within the cube (all index files and page files).

Restructure Types and Execution Times

The execution time of a restructure varies depending on the size of the files being restructured (the size of index and page files) and the number of existing database fragmentation. A high impact restructure (explicit restructure or Index and block implicit restructure) takes longer to finish compared to a low impact Index only or outline only restructure.

Monitoring the Size of Index and Page Files

The following rows in the Essbase BSO Cube Statistics table in the Activity Report identify the size of the index and page files. Look for the following rows in these tables:

  • Page File Sizes in MB
  • Index File Size in MB

Monitoring the Number of Blocks in BSO Cubes

The number of blocks in the cube is an excellent indicator of the size of BSO cubes. Empty blocks, which may be included in this block count, can be removed by running an explicit cube restructure (see Explicit Restructure).

If you want to find the number of empty blocks in a BSO cube before running an explicit restructure, use Calculation Manager to export level 0 data. Click Show Details when level0 export in Calculation Manager completes, assuming that the page doesn’t time out during the export process). After clicking the Show details, identify phrases similar to Total blocks: [124000]. Empty blocks: [1000]. Existence of a high number of empty blocks is an indication to run an explicit restructure, which will remove the empty blocks.