Big Data, Data Warehouses, and Business Intelligence Systems - Database Processing: Fundamentals, Design, and Implementation - page 561

The Data Mining
command tab
The Cluster Analysis
button
The connection to
SQL Server 2008
Analysis Services
The data table is in
the HSD-DW-SQL-
View-Results
worksheet
Figure 12-26
The Excel Data Mining
Command Tab
Office—this package runs with both Microsoft Office 2010 and Microsoft Office 2013. 5
Figure 12-26 shows Microsoft Excel 2013 with the Data Mining command tab and command
groups. With this add-in, data stored in Microsoft Excel are sent to SQL Server Analysis
Services for processing, and the results are returned to Microsoft Excel for display.
Distributed Database Processing
One of the first solutions to increase the amount of data that could be stored by a DBMS
system was to simply spread the data among several database servers instead of just one. A
group of associated servers are known as a server cluster , 6 and the database shared between
them is called a distributed database. A distributed database is a database that is stored and
processed on more than one computer. Depending on the type of database and the processing
that is allowed, distributed databases can present significant problems. Let us consider the
types of distributed databases.
Types of Distributed Databases
A database can be distributed by partitioning , which means breaking the database into
pieces and storing the pieces on multiple computers; by replication , which means storing
copies of the database on multiple computers; or by a combination of replication and parti-
tioning. Figure 12-27 illustrates these alternatives.
Figure 12-27(a) shows a nondistributed database with four pieces labeled W, X, Y, and Z.
In Figure 12-27(b), the database has been partitioned but not replicated. Portions W and X
are stored and processed on Computer 1, and portions Y and Z are stored and processed on
Computer 2. Figure 12-27(c) shows a database that has been replicated but not partitioned.
The entire database is stored and processed on Computers 1 and 2. Finally, Figure 12-27(d)
5 For more information and to download the Microsoft SQL Server 2012 SP1 Data Mining Add-ins for Microsoft
Office package, go to http://www.microsoft.com/en-us/download/details.aspx?id=35578 . Note, however, that
these add-ins will not work with SQL Server 2012 Express Edition—you have to have a version of SQL Server
with SQL Server Analysis Services.
6 For more information on computer clusters, see the Wikipedia article at http://en.wikipedia.org/wiki/
Server_cluster .