Archives of the TeradataForum

Message Posted: Thu, 13 Jan 2011 @ 14:23:25 GMT

	<Prev	Next>		<<First	<Prev	Next>	Last>>

Irfan,

Single amp operation:-

Usally teradata distributes rows based on hash value generated for every primary index values. Same primary index values should be have an same hash values. Occording to that if you defiend as unique primary index on table those rows are distributed evenly acorss the amps.in the sense one row for every amp.

Uneven data distribution happens incase if you defined as nupi.

So same primary index values should store on same amp. When you select the rows based on primary index vales that will point to the particular amp where that rows resides. That is called as one amp opertaion.

	<Prev	Next>		<<First	<Prev	Next>	Last>>