Test2008 Resurrecting The Prodigal Son Data Quality (http://www.geektester.blogspot.com)

Test2008 Resurrecting The Prodigal Son Data Quality (http://www.geektester.blogspot.com) - Presentation Transcript

Resurrecting the Prodigal Son - Data Quality “ Rise from Ashes: Battle of Data Quality Testing”

Speakers

Bhoomika Goyal

Working @ Microsoft for over an year

Engineer from Mumbai

Loves playing Chess, Solving Puzzles and Reading

Raj

W orking @ Microsoft Business Intelligence COE

5.5 + years of Testing experience

Loves watching movies, reading suspense thrillers & playing cricket

Passion - Testing ( http://www.itest.co.nr )

www.Test2008.in

Horror Story

Loss: $ 125 million

Reason: Discrepancy between the two

measures (rocket thrusts to newtons)

NASA Mars Climate Orbiter spacecraft LOST

www.Test2008.in

Bad, Bad, Bad Data Quality www.Test2008.in Erroneous Mailing hit $611 billion for US businesses in 2002

DQ is not my problem? Think Again !!!!! www.Test2008.in

DQ Hot Candidates www.Test2008.in Data Movement Migrations Backups Restore Import Export Data Warehousing Business Intelligence OLTP OLAP CRM ERP

DQ Ishikawa Diagram www.Test2008.in Bad Decisions (Loss $ & Customers) DQ Reqmts not documented Lack of white box testing Data is dynamic CRM & ERPs Implementations Mergers / Take Over

www.Test2008.in Data Quality DQ is an indicator that tells about the health of the DATA

www.Test2008.in GOOD Data Quality DQ is good if data is fit to use for decision making

www.Test2008.in Data Quality Testing

Involves validating , monitoring & reporting various attributes of Data

like

accuracy , validity , timeliness etc

DQ Checks www.Test2008.in Row Counts Consistency Referential Integrity Redundancy Usability Completeness Domain Integrity Timeliness Accuracy Validity

Row Count Check www.Test2008.in

Completeness Check www.Test2008.in

Among Voters seen Dead People www.Test2008.in US General Election: 4,755 deceased people voted

Consistency Check www.Test2008.in

A One-House, $400 Million Bubble Goes Pop www.Test2008.in $1,21, 000 overvalued at $ 400 million Govt. Expected $8 million as Tax Revenue

Accuracy Check www.Test2008.in

Validity Check www.Test2008.in

CD Mail Fraud

Man received 22,260 CDs at discounted price by making each address different enough

www.Test2008.in David Loshin 123 Main Street Any town, NY 11787 David Loshin 123 Main Street, Near Wal-Mart Any town, NY 11787

Redundancy Check www.Test2008.in

Referential Integrity Check www.Test2008.in

Domain Integrity Check www.Test2008.in

Timeliness www.Test2008.in

How do we test DQ? www.Test2008.in DQ Rule Engine Metadata Results Create Procedure RowCount (SrcTbl, TgtTbl) Begin Declare SRC, TGT Integer Select SRC = Count(*) from SrcTbl Select TGT = Count(*) from TgtTbl) If SRC = TGT Then Return “PASS” Else Return SRC – TGT End If End Metadata Results Row Count Logic Duplicate Logic Create Procedure Duplicate(Tbl) Begin Declare Dup Integer Select Dup = Count of Select * from Tbl GroupBy <<ColumnList>> Having count(*) > 1 If Dup = 0 Then Return “PASS” Else Return Dup End If End End Rule Tbl1 Tbl2 RC Emp Emp RI Emp Dept DC HR HR Rule Result Comment RC Pass - RI Fail 10 DC Pass -

You can’t improve what you can’t measure www.Test2008.in Threshold Time 5 % 10 % 100 % Data Quality Red: BAD DQ Yellow: Watch it Green: Good DQ

DQ Testing is your friend !!!