MurmurHash Example 1: 32-Bit Hash Value (by Default) - Teradata Vantage

Input

The input table, murmurhash_input, is a log of midnight temperatures (in degrees Fahrenheit) for five consecutive nights in five cities. The rows of all columns except id and city_varchar are converted to hash values. Because the hash value depends on data type, the input table has three columns each, with different data types, for the time period and temperature:

SQL Call

SELECT * FROM MurmurHash (
  ON murmurhash_input
  USING
  InputColumns ('[2:7]')
  Accumulate ('id')
) AS dt ORDER BY 1;

Output

The hash values for each time period are different for each data type. When the temperature value in the input table is an integer, the hash values are the same for INTEGER and VARCHAR, but different for REAL. When the temperature value in the input table is real, the hash values are the same for REAL and VARCHAR, but different for INTEGER.