Example: Showing the Count of Rows in Each Partition - Analytics Database - Teradata Vantage

SQL Functions, Expressions, and Predicates

Deployment
VantageCloud
VantageCore
Edition
Enterprise
IntelliFlex
VMware
Product
Analytics Database
Teradata Vantage
Release Number
17.20
Published
June 2022
Language
English (United States)
Last Update
2024-01-12
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lifecycle
latest
Product Category
Teradata Vantage™

The following example shows the count of rows in each partition if the orders table were to be partitioned using the CASE_N expression.

   CREATE TABLE orders 
    (orderkey INTEGER NOT NULL
    ,custkey INTEGER
    ,orderdate DATE FORMAT 'yyyy-mm-dd' NOT NULL)
    PRIMARY INDEX (orderkey);
   
   INSERT INTO orders (1, 1, '1996-01-01');
   INSERT INTO orders (2, 1, '1997-04-01');
   

The CASE_N expression in the following SELECT statement specifies three conditional expressions and the NO CASE condition.

   SELECT COUNT(*), 
          CASE_N(orderdate >= '1996-01-01' AND
                 orderdate <= '1996-12-31' AND
                 custkey <> 999999,
                 orderdate >= '1997-01-01' AND
                 orderdate <= '1997-12-31' AND
                 custkey <> 999999,
                 orderdate >= '1998-01-01' AND
                 orderdate <= '1998-12-31' AND
                 custkey <> 999999,
                 NO CASE
          ) AS Partition_Number
   FROM orders 
   GROUP BY Partition_Number 
   ORDER BY Partition_Number;

The results look like this:

      Count(*)  Partition_Number
   -----------  ----------------
             1                 1
             1                 2