Direct vs MSAS (or RadarCube editions)
Posted by Ivan Pashkov on 28 May 2013 04:32 PM
RadarCube for all platforms exists in two editions: Direct (sometimes also referred to as Desktop edition because it assumes working on a desktop computer) and MSAS (because of the MS Analysis Services OLAP server this edition connects to). This article explains the difference between these editions and helps choosing.
This edition works with relational databases. This assumes any data source that can be treated in table-relation terms. This can be an MS SQL Server database, Oracle, MS Access, MS Excel, you name it. It can be even a text file with the data in it. The Direct edition connects to the database and converts its data to an OLAP cube suitable for data analysis. In other words this edition has its own OLAP engine to build the cubes and process the queries to the cubes.
This edition only needs a connection to the database and corresponding data provider. It reads the database, builds the OLAP cube and then the database connection is no longer needed. The cube data can be saved to a file and later be restored without a database connection.
Unlike the Direct edition the MSAS edition is not able to build the cubes itself. It connects to an existing MS Analysis Services OLAP cube (it can be either a local cube or located on the server) and uses its data. This edition doesn’t have its own OLAP engine and cannot process the queries to the cube itself. Instead it delegates all the queries to the server and gets the result from the server. So it mostly operates like a client to the MSAS server, with additional features though.
This edition requires the MS Analysis Services server running on the network with the ready OLAP cubes in it.
What to choose
In most cases there is no question which RadarCube edition to choose because the data format dictates the choice. If you have the relational database then it is Direct, if you have MS Analysis Services OLAP cube then it is MSAS. However, often there can be some critical points that make one of them preferable. Here are some possible issues to review.
Performance and data size
The Direct edition processes all the queries itself and that means it operates with large amount of data on your desktop computer. So there is a limit on the data size anyway. And the more data the database has, the higher are the resources needed and less the performance. On the other hand the MSAS edition operates like a client to the server, so it only sends queries and receives the result, all calculations are performed on the server and very quick at that. This edition doesn’t depend on the size of your data because the OLAP server is designed specifically for large OLAP cubes and its performance will always be good.
So as a rule of thumb you should use the MSAS edition if there is the large amount of data in your database or if it is very likely to extend dramatically over time. And you should use the Direct edition for the relatively small databases (up to several million records in the fact table).
MSAS edition requires the server
The MSAS edition requires the OLAP server somewhere on the network. Needless to say that it means additional resources (time and money) to keep it up and running. Also this edition requires a special data provider (read “additional software”) installed on the client computer, and it’s often not an option.