Solved

OLAP - Basic How To

Posted on 2008-06-09
4
443 Views
Last Modified: 2013-11-16
I have a database that is a series of normalized and denormalized tables from various sources in a banking enterprise.  

In trying to build a basic OLAP cube should I create a star schema from these sources and link them with primary and foreign keys?

0
Comment
Question by:michaelrobertfrench
  • 2
4 Comments
 
LVL 12

Accepted Solution

by:
RWrigley earned 350 total points
ID: 21756271
Essentially, yes, but it depends on what kind of cube you're building.  If you're looking at SQL 2005, then creating a data warehouse will make building the cube much simpler, and will help ensure that you're able to get predictable and reliable results.  However, it's always possible to build your cube directly against the raw data.  The difference will be the amount of time it takes to process the cube.
0
 
LVL 8

Assisted Solution

by:srnar
srnar earned 150 total points
ID: 21758352
Do you really need an Olap? Will be end users doing analysis (using slicing, drill down etc.) or do you have end users only in reports? Are there some complicated aggregations (many levels,  distinct counts)?

As each of layers: it takes time to build, process and maintain.
0
 

Author Comment

by:michaelrobertfrench
ID: 21760683
This is a slice dice analysis type operation.  
A typical question posed to the OLAP might be:

How many transactions are made each month for those in a given credit score?

Basically, I am taking aggregates like:
Credit Card purchases, payments, interest paid, etc for each period

And putting them into dimensions like:
Branch Location, APR, credit score, number of transactions etc

I have written a sp that takes an integrated database(which has a utility in and off itself unrelated to OLAP) and creates a star schema that for my aggregates and dimensions.

Is this a typical method of deriving cubes and setting up an OLAP?
That is, a stored procedure to create an OLAP from an OLTP.
0
 
LVL 12

Assisted Solution

by:RWrigley
RWrigley earned 350 total points
ID: 21760838
No, the more typical solution would involve a ETL process to extract the data from your OLTP environment, transform it and load it into a dedicated data warehouse.  

As a general rule, OLTP database's are optimized for rapid posting of new data.  You wouldn't normally want to do any kind of reporting (OLAP or otherwise) against these database, becuase they dont' have the indexes required to process these efficiently.  And you wouldn't want to ADD those indexes to an OLTP database, becuase of the potential performance hit (indexs increase write time).

What IS somewhat common is using a SP as part of the ETL process, especially in cases where the ETL process isn't all that robust or is spanning database types.
0

Featured Post

Microsoft Certification Exam 74-409

Veeam® is happy to provide the Microsoft community with a study guide prepared by MVP and MCT, Orin Thomas. This guide will take you through each of the exam objectives, helping you to prepare for and pass the examination.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

Title # Comments Views Activity
Client backup and data retention? 3 62
ODBC Question 3 40
Exchange 2007 standard - defrag (eseutul /d) 10 39
SYbase 4 27
This article describes some very basic things about SQL Server filegroups.
These days, all we hear about hacktivists took down so and so websites and retrieved thousands of user’s data. One of the techniques to get unauthorized access to database is by performing SQL injection. This article is quite lengthy which gives bas…
Video by: Steve
Using examples as well as descriptions, step through each of the common simple join types, explaining differences in syntax, differences in expected outputs and showing how the queries run along with the actual outputs based upon a simple set of dem…
Polish reports in Access so they look terrific. Take yourself to another level. Equations, Back Color, Alternate Back Color. Write easy VBA Code. Tighten space to use less pages. Launch report from a menu, considering criteria only when it is filled…

785 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question