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

SQL Data Manipulation Language

Product
Teradata Database
Teradata Vantage NewSQL Engine
Release Number
16.20
Published
March 2019
Language
English (United States)
Last Update
2019-05-03
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fbo1512081269404.ditamap
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TD_DBS_16_20_Update1.ditaval
dita:id
B035-1146
lifecycle
previous
Product Category
Teradata Vantage™

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);