17.05 - Example: Using the RANDOM Option to Randomly Redistribute Data Blocks of Rows and Individual Rows Before Copying Them Locally - Advanced SQL Engine - Teradata Database

Teradata Vantage™ - SQL Data Manipulation Language

Product
Advanced SQL Engine
Teradata Database
Release Number
17.05
Release Date
January 2021
Content Type
Programming Reference
Publication ID
B035-1146-175K
Language
English (United States)

Assume that you created the following NoPI tables for this example.

     CREATE TABLE tnopi1 (
       a INT,
       b INT,
       c INT)
     NO PRIMARY INDEX;

     CREATE TABLE tnopi2 (
       a INT,
       b INT,
       c INT)
     NO PRIMARY INDEX;

The following INSERT …  SELECT request uses the RANDOM option to redistribute data blocks of rows randomly from tnopi1 before locally copying them into tnopi2.

     INSERT INTO tnopi2
       SELECT *
       FROM tnopi1
       HASH BY RANDOM;

The following INSERT …  SELECT request uses the RANDOM function to redistribute individual rows randomly from tnopi1 before locally copying them into tnopi2:

     INSERT INTO tnopi2
       SELECT *
       FROM tnopi1
       HASH BY RANDOM(1, 2000000000);