Is there a performance overhead using Composite Primary Indexes?

Database
Fan

Is there a performance overhead using Composite Primary Indexes?

Hi,

 

Can anyone tell me if there is a Performance Overhead when using Composite Primary Indexes?

 

Does Teradata have to "build" the Primary Index with all the Composite columns before it can be passed through the Hash algorithm?

 

Thanks,

 

Kirbs 

  • Composite
  • Primary Index
2 REPLIES
Teradata Employee

Re: Is there a performance overhead using Composite Primary Indexes?

There is nothing to build for a Primary Index.  It is not an index in the traditional sense.  There is no file anywhere; it is just an arithmetic process to generate an AMP number and location.  If the input (the concatenation of all the columns in the PI) is longer, then it will take a little more CPU to generate the hash, but it will be such a small difference you won't notice.  It's really nothing compared to all the other work a PE has to do.

Fan

Re: Is there a performance overhead using Composite Primary Indexes?

Thanks,

 

I thought that was the case.

 

Kirbs