Primary Index vs. Primary AMP Index

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sri
N/A

Primary Index vs. Primary AMP Index

Hi Experts,
Can some explain me the difference between Primary Index and Primary AMP Index? I read that a table in Teradata can create a Primary Index by default but not Primary AMP Index....please help on this too.....

Thanks in advance.
Sri.
  • Teradata Index
3 REPLIES
Teradata Employee

Re: Primary Index vs. Primary AMP Index

Primary AMP allows the distribution to be specified for a NOPI table. The column(s) specified are hashed and the rows are distributed according to that hash. Once hashed to an AMP, the rows are appended rather than sorted by hash as they are in a PI table.
sri
N/A

Re: Primary Index vs. Primary AMP Index

Hi Todd,

 

Thanks for posting answer. A NoPI table doesn't have any PI, then which column is considered for distribution and how PE can identify that column? could you please explain?

 

Thanks,

Sri.

Teradata Employee

Re: Primary Index vs. Primary AMP Index

primary amp is a clause similar to primary index and is specified on the create table definition for a nopi table.