How Unique determines which value to take

[Jack_Nelson]

I'm querying a server at certain points in time and trying to append any new rows/update changed values.  The information is continuous in time with datestamps for when something occurred and when a field was last updated.  To carry out the new output I thought the easiest approach would be to union the existing alteryx database with the queried data and taking the latest [update datestamp] row for every [event datestamp].  I thought this can be accomplished with the unique tool but wanted to confirm that it computes in a linear fashion (top to bottom) so when I sort in descending [update datestamp] by [event datestamp] it will populate the first row in the unique output. i.e. 

Update Datestamp       Event Datestamp

01/02/2017 11:22:33    01/01/2017 03:04:05  <-This line taken to "U" output in Unique Tool

01/01/2017 10:20:30    01/01/2017 03:04:05  <-Next 2 lines taken to "D" output in Unique Tool

01/01/2017 04:05:06    01/01/2017 03:04:05

[Jack_Nelson · Accepted solution]

Answered my own question...it appears that is exactly how the unique tool works.  I should have read the Tool Mastery | Unique page first.