The Dire Consequences of Your Flawed Database …white_paper/TheDireConsequences.pdf · validation...

validation for flawless schemas

The Dire Consequences of Your

Flawed Database Schemas

Prepared by:Luiz C. Siqueira

DBE Software

[email protected]

+1-703-847-9500


Facts DWI – 50%+ of Data warehouse projects fail to poor information

DQI – Cost of poor information = 25% of budget

LCS – Current schemas are extremely large and complex; every schema that I reviewed (2000+) had major flaws

Flawed Schemas

Poor quality of informa7on

Poor performance

Late delivery of applica7ons

Increased development cost


Consequences of a flawed schema?


Poor quality of informa7on

Poor performance

Schema Issues?

Joe Celko quote Joe Celko, one of the top database experts and published author, states in his paper It’s the Code, Stupid!:

“A poorly designed database schema affects negatively the quality of the information and

the performance of the application”


Schemas have flaws

Poor quality of information

Poor performance

•  Development costs are high


h Schema Issues?

Late delivery of applications


Consequences of a late schema validation?


Data Model Schema

DDLScripts

Applications Errors? End

ApplicationErrors

Yes

No

Type?

Modeling ToolStart

Schema Issues?


Data Model Schema

DDLScripts


Yes

No

Type?

Modeling ToolStart

SchemaErrors

Schema Issues?


ApplicationErrors

Schema Errors are detected after: a) Database is populated with data b) Application programs are written

Changes to the Schema may require: a) Part of the data to be offloaded b) Schema to be re-designed and tested

c) Data to be uploaded (eventually to different tables) d) Affected programs to be modified & re-tested Consequences of schema issues being fixed late:

a) Late Delivery of Applications b) Increased Development Cost

Schema Issues?


Schema Issues?

Schemas fixed late




Schema Issues?

Schemas have flaws

•  Performance is not at peak

•  Information has poor quality •  Poor performance

•  Poor quality of information Schemas fixed late

It is all about the database schemas!!!

Poor quality of information

Poor performance




So, we know…

Most current schemas have flaws It is imperative to validate & fix flawed schemas Validation must be based on:

Relational Model Performance best practices

This validation must be done very early in the process


Schemas Fixed

Fixing the schemas early à all issues resolved

Schemas fixed early

Applica7ons delivered on 7me

Development cost at budget

Schemas have

no flaws

Pris7ne Informa7on

Performance at Peak


Flawless Schemas

(fixed early)

Pris7ne Informa7on

Peak Performance

Applica7ons delivered on 7me



Options for Schema Validation 1 – Manual Validation – Extremely time consuming, not all the issues will be detected

2 – Create DDL Scripts – Better than option 1, but still time consuming and not all issues will be detected; someone must keep updating the scripts

3 – Validation with a Software Tool – Most effective, every schema will be validated using the same criteria, all issues can be detected and corrective scripts may be generated


Welcome to Database Examiner

Inputs: •  ERwin physical data models •  SQL/DDL scripts •  Database schemas (DB2, ORACLE, SQL Server, etc)


Knowledge Bases (KBs) 1.  Relational model (80%) 2.  Industry performance best practices (20%)


Knowledge Bases (KBs) 1.  Relational model (80%) 2.  Industry performance best practices (20%)

All validations will be based on the same criteria


Database Examiner

ERwin

DDL Scripts

DB Schemas

TeachMe

Remediation Scripts

ER Diagram

Documentation

Diagnostics (60+)


Diagnostic – Table & Column

Table & Column

Index & Constraint

Diagnostic – Index & Constraint

Normaliza6on

Diagnostic – Normalization

Rela6onship

Diagnostic – Relationships

User Defined

Diagnostic – User Defined

Benefits of Database Examiner Validation Schemas will be evaluated by a standard criteria - Relational Model - Performance Best Practices

All schema issues will be detected & explained

Remediation scripts will be generated

Performance will be increased

Information will have quality

Examiner pays for itself many times over


I mentioned other benefits Applications being delivered on schedule



Schemas fixed early

Applica7ons delivered on schedule



Schema is developed & validated

Modeling Tool

Data Model Schema

DDLScripts


ApplicationErrors

Yes

SchemaErrors

No

Errors?

Yes No

SchemaValidation

Start

Debugging the Schema Debugging the Application

CertifiedSchema

Proposed Development Process


Schema is developed & validatedThen application code is developed & debugged

Modeling Tool

Data Model Schema

DDLScripts


ApplicationErrors

Yes

SchemaErrors

No

Errors?

Yes No

SchemaValidation

Start

Debugging the Schema Debugging the Application

CertifiedSchema

Proposed Development Process


Schema is merged with proposed changesIf errors are detected, proposed changes must be fixed

Proposed ChangesDDL Scripts

Errors?

Yes

No

SchemaValidation

NewCertifiedSchema

CertifiedSchema

Proposed Maintenance Process


Conclusions •  We are designing flawed schemas

•  Flawed schemas are the culprit for major issues

•  Schema validation is NOT OPTIONAL

•  Database Examiner helps produce flawless schemas

•  2,500+ organizations use Database Examiner

•  If schema is flawless, then Information Quality à Reality

•  The choice is yours

Schemas must be pristine


To test Database Examiner •  Go to www.dbesoftware.com/products/download

•  Register for the download

•  Perform the download

•  Send us the email prepared by the product

•  DBE Software will send you the unlocking code

•  Install the unlocking code

•  You are good to go for 10 days of testing



Contact DBE Software

Tom SterbutzelDBE Software [email protected] +1-703-847-9500 – DBE +1-703-927-2077 – Mobile


The Dire Consequences of Your Flawed Database …white_paper/TheDireConsequences.pdf · validation...

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