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Posts Tagged ‘Data Warehouse’

What is ODS (Operational Data Store) and how it differs from Data Warehouse (DW)

December 17, 2014 2 comments

I see lot of people discussing about ODS, and citing their own definitions and ideas about it. Some people also use the name as a synonym for a Data Warehouse or Factory Database. Thus, at times it becomes very difficult to tell or convince people while you are designing or architecting a DW/BI solution.
 

So, I thought to give some time to explain what actually an ODS is.
 

Simple definition: An Operational Data Store (ODS) is a module in the Data Warehouse that contains the most latest snapshot of Operational Data. It is designed to contain atomic or low-level data with limited history for “Real Time” or “Near Real Time” (NRT) reporting on frequent basis.
 

Detailed definifion:

– An ODS is basically a database that is used for being an interim area for a data warehouse (DW), it sits between the legacy systems environment and the DW.

– It works with a Data Warehouse (DW) but unlike a DW, an ODS does not contain Static data. Instead, an ODS contains data which is dynamically and constantly updated through the various course of the Business Actions and Operations.

– It is specifically designed so that it can Quickly perform simpler queries on smaller sets of data.

– This is in contrast to the structure of DW wherein it needs to perform complex queries on large sets of data.

– As the Data ages in ODS it passes out of the DW environment as it is.
 

–> Where does ODS fits in a DW/BI Architecture?

ODS_DW
 

–> Classes of ODS (Types):

Bill Inmon defines 5 classes of ODS shown in image below:

Class-1 ODS would simply involve Direct Replication of Operational Data (without Transformations), being very Quick.

– Whereas Class-5 ODS would involve high Integration and Aggregation of data (highly Transformed), being a very time-consuming process.

ODS2
 


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Preparing for 70-463 Exam : Implementing a Data Warehouse with Microsoft SQL Server 2012

December 5, 2013 19 comments

After passing 70-461 exam last year I’m now preparing for 70-463 exam i.e. Implementing a Data Warehouse with Microsoft SQL Server 2012. This exam mainly focuses on implementing Data Warehouses with Dimension & Fact tables, working with SSIS packages and Data Quality solutions. Thus being a Database Developer (primarily) this exam will be bit tough for me as I’ve not worked with Dimensional modelling, SSIS and DQS.

For preparation I’m referring to Training Kit (Exam 70-463) Implementing a Data Warehouse with Microsoft SQL Server 2012 book.

This exam is primarily intended for ETL and Data Warehouse (DW) developers who create Business Intelligence (BI) solutions, and whose responsibilities include Data Cleansing, and Extract Transform Load and Data Warehouse implementation.
 

–> The Exam is divided into 5 modules:

1. Design and Implement a Data Warehouse | 11%
– Introducing Star and Snowflake Schemas
– Design and Implement Dimensions
– Design and Implement Fact tables
– Managing the Performance of a Data Warehouse
– PREP links: Introduction to dimensions (Analysis Services – multidimensional data) | Dimension relationships | Columnstore indexes

2. Extract and Transform data | 23%
– Define Connection managers
– Design Data Flow
– Implement Data Flow with Transformations
– Control Flow tasks and Containers, Precedence Constraints
– Manage SSIS package execution
– Implement Script tasks in SSIS
– PREP links: Integration Services (SSIS) connections | Data flow | Slowly changing dimension transformation

3. Load Data | 27%
– Design control flow
– Implement package logic by using SSIS variables and parameter
– Implement Control flow
– Implement Data Load options
– Implement Script components in SSIS
– Slowly Changing Dimensions
– Preparing a Package for Incremental Load
– Package Transactions, Checkpoints, Event Handlers
– PREP links: Integration Services transactions | Developing a custom task | Integration Services (SSIS) parameters

4. Configure and Seploy SSIS solutions | 24%
– Troubleshoot Data Integration issues
– Install and Maintain SSIS components
– Implement Auditing, Logging, and Event handling
– Deploy SSIS solutions
– Configure SSIS security settings
– Data Mining Task and Transformation
– Preparing Data for Data Mining
– Implementing SSIS Fuzzy Transformations
– PREP links: Troubleshooting tools for package development | Load-balancing packages on remote servers by using SQL Server Agent | Integration Services (SSIS) logging

5. Build Data Quality Solutions (DQS) | 15%
– Install and maintain Data Quality services
– Creating and Maintaining a Knowledge Base
– Create a Data Quality project to clean data, Profiling Data and Improving Data Quality
– Using DQS and the DQS Cleansing Transformation
– Implement Master Data Management (MDM) solutions
– Using Master Data Services Add-in for Excel
– PREP links: Install Data Quality Services | Install Master Data Services | Master Data Services features and tasks
 

-–> You can visit following Study materials to prepare for this Exam:

Microsoft Link for this Certification: http://www.microsoft.com/learning/en-us/exam-70-463.aspx

Book on AMAZON.com: Training Kit (Exam 70-463) Implementing a Data Warehouse with Microsoft SQL Server 2012
 

I will try to update this blog post or will put up a new post with my learning while preparing for this exam.

All The Best!!!