Ramifications of Rebuild Cube Options

Ramifications of Rebuild Cube Options

There are important differences in the ramifications of the three Rebuild Cube options. By reading this topic, you can make an informed choice and achieve your desired outcome. The Rebuild Cube dialog has these three rebuild types:

rebuildcubetypes.png

Figure 1.    Rebuild Types for Cubes

The following table summarizes the key features and ramifications for each of these rebuild options.

Table 1.       Rebuild Cube Options

Rebuild Cube Option

Ramifications

Refresh Fact Data Only

  • Deletes all Fact Data  in a Cube (except  members whose data has been marked as “persistent”*)

  • Refreshes with current Fact Data from the relational data source

  • Retains the original Dimension members and Hierarchy

Does NOT:

  • affect other Cubes with shared Dimensions

  • add any  new members from the relational source that are not currently in the Cube’s Dimensions (e.g., new customer names)

Add Metadata and Refresh Fact Data

  • Performs all of the actions listed above in “Refresh Fact Data Only,” but also appends Cube hierarchies based on the relationaldatabase, adding any new members from the source not currently listed in the Dimensions (e.g., names and data for new customers since last Fact Data Refresh).

  • Unless you select the Rebuild Hierarchies option, retains the existing cube Hierarchies that came from the source database and Hierarchies that you created in proCube. This function adds to the cube any data and Hierarchies from the relational database that are not found in the cube.

Does NOT:

  • affect other Cubes with shared Dimensions

  • remove existing elements of a hierarchy unless you select the Rebuild Hierarchies option. (So if there are hierarchical changes in your relational source data, and you choose to add Metadata, you may have duplications in the Hierarchy of your Cube’s Dimensions. To avoid this problem, consider the Rebuild Hierarchies or the Rebuild Metadata option below).

Rebuild Metadata and Refresh Fact Data

  • Exports Fact Data and Metadata in Cubes which share Dimensions with the Cube that is being rebuilt, including subsets and slices.

  • Deletes all Fact Data from the Cube (except  members whose data has been marked as “persistent”*)

  • Removes all Members from the Cube’s Dimensions (except  members whose data has been marked as “persistent”*)

  • Removes manually-created hierarchies from the Cube (i.e., hierarchies that were not taken from the relational data source, but rather were created manually  in the Cube)

  • Re-creates Members and hierarchies of Members based on data in the relational data source

  • Reloads current Fact Data from the relational data source

  • Reloads Fact Data and Metadata in Cubes which used shared dimensions with the Cube that is being rebuilt

The Rebuild Metadata option can be performed quickly on Cubes that are largely populated with transactional data obtained directly from the relational data source (and have little manually inputted data). But the Rebuild Metadata process takes longer with Cubes that have a significant amount of manually inputted data because proCube must first export all of this data and store it so that it is not deleted during the Cube rebuild. After the Cube rebuild, proCube will automatically import this saved data back into your Cube.

The following table presents an alternative approach to understanding the differences between the Rebuild Cube options.

Table 2.       Alternative View - Rebuild Cube Options

 

Fact Data Only Operation

Add Metadata Operation (default)

Rebuild Metadata Operation

Clears and Reloads Fact Data

YES

YES

YES

Adds New Metadata

NO

YES

YES

Recognizes deleted Table Member (i.e., it no longer appears)

NO

NO

YES

“Gets rid of “ Member created in proCube

NO [If Persist* is used, Fact Data remains as is]

NO [If Persist* is used, Fact Data remains as is]

YES [If Persist* is used, Fact Data remains as is] **

“Tosses out” Member from proCube-created Hierarchy

NO

NO

NO

Zeroes out “Transfer Cube” data in 2nd Cube

NO

NO

YES

Zeroes out “Formula” data in 2nd Cube

NO

NO

NO

*The Mark Member as Persistent option (= “Persist”) enables you to “save from deletion” a proCube-created Member. DO NOT use Persist feature on a Member that has been generated from underlying relational tables. The above bracketed statements are valid when that “Multidimensional Editing Allowed” option is enabled.

 

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