October Is Scary Schema Month

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October Is Scary Schema Month

Ayende kicked the month off with "Schema to wince by…", then "CRM Horror".

Great timing, Ayende! With Halloween right around the corner, let's make October scary schema month!

Here is one that recently made my hair stand on end:

        
            ALTER TABLE [dbo].[EmergencyPatientAssesments]
            
            ADD CONSTRAINT [mspk550470] 
                PRIMARY KEY CLUSTERED
            
        ( 
            
        [BaseID] 
            ASC, 
                
                    [PatientVisitID] ASC,
                    
                [TreatmentID]
                    ASC, 
                        
        [DateTime] 
            ASC, 
                
                    [ActualDateTime] ASC,
                    
                [AssessmentSequenceID]
                    ASC, 
                        
        [QuestionID] 
            ASC 
            
        ) 
                    ON [PRIMARY]

This healthcare schema defines a composite primary key using 5 varchar fields and 2 datetime fields. If you think the index is scary, you should see the joins…

Do you have a scary schema to share?

Print | posted @ Wednesday, October 10, 2007 1:12 AM

Comments on this entry:

# re: October Is Scary Schema Month

by Sahil Malik at 10/10/2007 1:33 AM

EEEeeeeeeeeeeeeeeeeeeeeeeeek!!

# re: October Is Scary Schema Month

by Simon at 10/10/2007 3:53 AM

After discussing this with team mates the feeling was that this is fine for a fact table in a data warehouse using a star schema.

Was a new one on me but..

http://en.wikipedia.org/wiki/Star_schema

# re: October Is Scary Schema Month

by scott at 10/10/2007 4:03 PM

Technically correct, but still scary ;)

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