Knowledge Drop

What does the MD5 function do?

  • 5 April 2021
  • 1 reply

Userlevel 5
  • Looker Staff
  • 172 replies

Last tested: March 2021



MD5 is just a hash that turns strings into hashes.

It's useful for making IDs out of a concatenation of several fields, which makes it valuable for joins. Looker uses it in symmetric aggregates.


select md5('Amazon Redshift'); md5  ----------------------------------  f7415e33f972c03abd4f3fed36748f7a  (1 row)

Great blog explaining it.


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1 reply

Userlevel 3

In addition to the linked community article on symmetric aggregates, there is an explanation of why symmetric aggregates look complicated here: