Now I let Vertica choose for us via a simple User Defined SQL Function!
Example:
dbadmin=> CREATE OR REPLACE FUNCTION coin_flip() RETURN VARCHAR(5)
dbadmin-> AS
dbadmin-> BEGIN
dbadmin-> RETURN CASE RANDOMINT(2)
dbadmin-> WHEN 0 THEN 'HEADS'
dbadmin-> WHEN 1 THEN 'TAILS'
dbadmin-> END;
dbadmin-> END;
CREATE FUNCTION
dbadmin=> SELECT coin_flip, COUNT(*) FROM (SELECT coin_flip() AS coin_flip FROM big_table LIMIT 100000) foo GROUP BY coin_flip;
coin_flip | COUNT
-----------+-------
TAILS | 49899
HEADS | 50101
(2 rows)
dbadmin=> SELECT coin_flip, COUNT(*) FROM (SELECT coin_flip() AS coin_flip FROM big_table LIMIT 100000) foo GROUP BY coin_flip;
coin_flip | COUNT
-----------+-------
TAILS | 49848
HEADS | 50152
(2 rows)
Helpful Links:
https://www.vertica.com/docs/latest/HTML/Content/Authoring/SQLReferenceManual/Statements/CREATEFUNCTIONSQLFunctions.htm https://www.vertica.com/docs/latest/HTML/Content/Authoring/SQLReferenceManual/Functions/Mathematical/RANDOMINT.htm
Have fun!
About the Author
James Knicely
Vertica Field Chief Technologist
I've had the privilege of working with many database technologies in my career. But after being introduced to Vertica in May of 2011 as a client, I was hooked on the new technology after witnessing a query run in milliseconds that had previously ran for hours on the legacy database we had in place. It was then that I knew I wanted to eventually join the Vertica team, and 4 years later I did! I am currently a Vertica evangelist and am ready to help you get on board! Please feel free to reach out to me with any questions you have about Vertica and make sure to follow my Vertica Quick Tips!
