Data Warehouse Concepts - Data Warehouse Systems: Design and Implementation - page 81

mode. Further, the data volumes supported by the tabular mode are smaller
than those of the multidimensional mode in Analysis Services. From the query
language perspective, each of these modes has an associated query language,
MDX and DAX (Data Analysis Expressions), respectively. Finally, from the
data access perspective, the multidimensional mode supports data access in
MOLAP (multidimensional OLAP), ROLAP (relational OLAP), or HOLAP
(hybrid OLAP), which will be described in Chap. 5 . On the other hand,
the tabular mode accesses data through xVelocity, an in-memory, column-
oriented database engine with compression capabilities. We will cover such
databases in Chap. 13 . The tabular mode also allows the data to be retrieved
directly from relational data sources.
In this topic, we cover only the multidimensional mode of BISM as well as
the MDX language.
3.6.2 Overview of Pentaho Business Analytics
Pentaho Business Analytics is a suite of business intelligence products.
It comes in two versions: an enterprise edition that is commercial and
a community edition that is open source. The main components are the
following:
￿ Pentaho Business Analytics Platform serves as the connection
point for all other components. It enables a unified, end-to-end solution
from data integration to visualization and consumption of data. It also
includes a set of tools for development, deployment, and management of
applications.
￿ Pentaho Analysis Services ,alsoknownas Mondrian , is a relational
OLAP server. It supports the MDX (multidimensional expressions) query
language and the XML for Analysis and olap4j interface specifications. It
reads from SQL and other data sources and aggregates data in a memory
cache.
￿ Pentaho Data Mining uses the Waikato Environment for Knowledge
Analysis (Weka) to search data for patterns. Weka consists of machine
learning algorithms for a broad set of data mining tasks. It contains
functions for data processing, regression analysis, classification methods,
cluster analysis, and visualization.
￿ Pentaho Data Integration ,alsoknownas Kettle , consists of a data
integration (ETL) engine and GUI (graphical user interface) applications
that allow users to define data integration jobs and transformations. It
supports deployment on single node computers as well as on a cloud or a
cluster.
￿ Pentaho Report Designer is a visual report writer that can query and
use data from many sources. It consists of a core reporting engine, capable
of generating reports in several formats based on an XML definition file.