15.00 - Special Considerations for NUSI Size Estimates - Teradata Database

Teradata Database Design

Product
Teradata Database
Release Number
15.00
Content Type
User Guide
Publication ID
B035-1094-015K
Language
English (United States)

Special Considerations for NUSI Size Estimates

The number of AMPs in the configuration are an important factor in estimating the total size of any NUSIs defined on a base table, as summarized in the following table:.

 

IF the number of AMPS is …

THEN at least …

AND the result is that …

less than the number of rows per value

one row from each NUSI value is probably distributed to each AMP.

  • Every AMP has every value.
  • Every AMP has a subtable row for every value.
  • greater than the number of rows per value

    some AMPs are missing some NUSI values.

  • Not every AMP has every value.
  • Not every AMP has a subtable row for every value.