Home Page for the TeradataForum

Archives of the TeradataForum

Message Posted: Wed, 14 Dec 2011 @ 20:05:48 GMT

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

Subj:   Re: Insert load half of my data
From:   Diehl, Robert


It is most likely that the target table is a "Set" table.

A "SET" table will not allow total duplicate rows (two or more rows with the contents of all columns being the same). "insert into" will silently delete them. You could change the target to a "MULTISET" table.

Following is the first part of a create table the difference between the ddl. Just change SET to MULTISET or vice versus.

Set table:

     CREATE SET TABLE db1234.table1234 ,NO FALLBACK ,...

Multiset table:

     CREATE MULTISET TABLE db1234.table1234 ,NO FALLBACK ,...

If you are just starting with Teradata, the most important choice you can make on a table is the primary index choice.

There are all kinds of threads and documentation about it. Please make sure you understand this concept.

Basically you want to choose a column or columns that are nearly unique (less than about 5000 rows per value).

Of the many choices, you also want to choose the one that will be most often used in joins or filters.

Most of the time you will want the same primary index on tables that are joined:

Column needs to be used in equal condition join ie table1.col1 = table2.col1

Both tables primary indexes need to be unique or nearly unique.


Robert Diehl
Travelocity Data Warehouse DBA

  <Prev Next>   <<First <Prev Next> Last>>  
  Top Home Privacy Feedback  
Copyright for the TeradataForum (TDATA-L), Manta BlueSky    
Copyright 2016 - All Rights Reserved    
Last Modified: 15 Jun 2023