Jan 26, 2021

Clickhouse Tips #1: Calculating Aggregations After a Given Date

Tips and recipes to learn how to make the most of ClickHouse, curated weekly by the Tinybird team.
Javier Santana
Co-founder

Imagine you have a table like

And you want to calculate, per day, the sum(amount) of previous and following days.

For example, for the day 2020-01-05 you have to calculate sumIf(amount, ts < '2020-01-05') and sumIf(amount, ts >= '2020-01-05')

I think there are many ways to do it but this works:

Check out this snapshot for a step-by-step explanation of what’s going on here.

I think a way to exploit that values for each day don’t need to be calculated every time for each day using a nice function, arrayCumSum, plus some other array magic.

Check this out for a step-by-step explanation.

I feel there should be an easier way but that’s just a feeling.

Do you like this post?

Related posts

ClickHouse tips #5: Adding and subtracting intervals
Roll up data with Materialized Views
ClickHouse tips #9: Filling gaps in time-series on ClickHouse
ClickHouse tips #3: the transform function
ClickHouse Tips #12: Apply Functions to Columns with a Single Call
Tinybird
Team
Sep 29, 2021
Tinybird is out of beta and open to everyone
ClickHouse tips #7: Forward and backfilling null values
We launched an open source ClickHouse Knowledge Base
Tinybird
Team
Oct 11, 2022
The data rules worth $40,000 a day
Real-Time Analytics: Examples, Use Cases, Tools & FAQs
Tinybird
Team
Mar 17, 2023

Build fast data products, faster.

Try Tinybird and bring your data sources together and enable engineers to build with data in minutes. No credit card required, free to get started.
Need more? Contact sales for Enterprise support.