Repeat last known value

Fri, 18 Jul 2025 00:00:00 +0000

Demo scripts below.

Disclaimer: This technique is by no means something I have come up with, I’ve just needed it enough times that I figured I might as well put it into my own words, for future reference.

Background

Suppose you have a collection of time series data, recording some status or other measurement at a point in time.

In an OLTP system we probably don’t want to repeat the same value every time we take a measurement, or we may only record changes made to a ledger when they occur.

Window Functions on Morten Ankerstjerne

Repeat last known value

Background