SAMPLEID Expression Examples | SQL SELECT Statements | Teradata Vantage - SAMPLEID Expression Examples - Analytics Database - Teradata Vantage

Example: Three Sample Sets Using SAMPLEID as a Select List Expression

The following SELECT statement provides three mutually exclusive sample sets (60 percent for sample category x, 25 percent for sample category y, and 15 percent for sample category z) from a customer table.

The results are returned in a table with three columns: cust_name, cust_addr, and SAMPLEID.

The integer in the SAMPLEID column identifies whether the row belongs to the 0.6 sample, the 0.25 sample, or the 0.15 sample.

The samples are identified as 1 through 3, in left-to-right order from the SAMPLE clause, so 0.6 is identified by 1, 0.25 by 2, and 0.15 by 3.

     SELECT cust_name, cust_addr, SAMPLEID
     FROM customer_table
     SAMPLE 0.6, 0.25, 0.15;

A partial results table might look something like the following:

Example: Using SAMPLEID With PERIOD Value Expressions

The following example shows how you can specify a PERIOD value expression with a SAMPLEID expression, where period_of_stay is the PERIOD value expression.

     SELECT emp_no, period_of_stay, SAMPLEID
     FROM employee
     SAMPLE 0.5,0.5;