SSAS: Processing Options

In previous posts we have already covered why processing the cube is important, in this post we look at the various processing options available within Analysis Services. The below table has been reference from the MSDN website and neatly outlines the different options and the scenarios in which they are applicable. Usually process default works well for most cases. However there may be different scenarios where other processing options may be employed.

 

Mode

Applies to

Description

Process Default

Cubes, databases, dimensions, measure groups, mining models, mining structures, and partitions.

Detects the process state of database objects, and performs processing necessary to deliver unprocessed or partially processed objects to a fully processed state. If you change a data binding, Process Default will do a Process Full on the affected object.

Process Full

Cubes, databases, dimensions, measure groups, mining models, mining structures, and partitions.

Processes an Analysis Services object and all the objects that it contains. When Process Full is executed against an object that has already been processed, Analysis Services drops all data in the object, and then processes the object. This kind of processing is required when a structural change has been made to an object, for example, when an attribute hierarchy is added, deleted, or renamed.

Process Clear

Cubes, databases, dimensions, measure groups, mining models, mining structures, and partitions.

Drops the data in the object specified and any lower-level constituent objects. After the data is dropped, it is not reloaded.

Process Data

Dimensions, cubes, measure groups, and partitions.

Processes data only without building aggregations or indexes. If there is data is in the partitions, it will be dropped before re-populating the partition with source data.

Process Add

Dimensions, measure groups, and partitions

Note

Process Add is not available for dimension processing in Management Studio, but you can write XMLA script performs this action.

For dimensions, adds new members and updates dimension attribute captions and descriptions.

For measure groups and partitions, adds newly available fact data and process only to the relevant partitions.

Process Update

Dimensions

Forces a re-read of data and an update of dimension attributes. Flexible aggregations and indexes on related partitions will be dropped.

Process Index

Cubes, dimensions, measure groups, and partitions

Creates or rebuilds indexes and aggregations for all processed partitions. For unprocessed objects, this option generates an error.

Processing with this option is needed if you turn off Lazy Processing.

Process Structure

Cubes and mining structures

If the cube is unprocessed, Analysis Services will process, if it is necessary, all the cube’s dimensions. After that, Analysis Services will create only cube definitions. If this option is applied to a mining structure, it populates the mining structure with source data. The difference between this option and the Process Full option is that this option does not iterate the processing down to the mining models themselves.

Process Clear Structure

Mining structures

Removes all training data from a mining structure.

 

The most common processing options that most developers are likely to use are

 

Process Default: – Usually when processing directly from the SSMS IDE

Process Full- Used when the cube is deployed for the first time or after major changes to the cube design and structures. It’s a good idea to process the cube in this mode periodically to ensure the cube and all its partitions are up to date and in sync.

Process Update – Used after making changes to the dimensions, especially useful when working with very large dimensions that take a long time to process.

Process Add – A very useful processing option however since it’s not available within the IDE the developer will need to write XMLS scripts in order to use this. This is the best processing option to make sure the cube processed quickly as it identifies the changes within the measures and the facts and then performs the processing.

Process Data – When restoring very large Cube its sometimes recommended to use this option as it ensure the cube will be available for querying sooner than other options. However since the indexes have not be processed performance could be drastically impacted.

 

Reference

http://msdn.microsoft.com/en-us/library/ms174774.aspx