Sisense Blog

By Maria Ciampa November 12, 2024

5 Compelling reasons to meet with Sisense at AWS re:Invent

What: Sisense at AWS re:Invent
Date: December 2-6, 2024
Where: Las Vegas, NV
Booth: 225

By Maria Ciampa August 20, 2024

Will AI data analytics tools assist or replace data engineers?

Discover how AI data analytics tools assist data engineers in seven key ways, including automating routine tasks and supercharging data prep and ETL processes.

By Paul Turner and Maria Ciampa August 14, 2024

4 Strategies for success with AI, machine learning, and analytics

Explore top AI machine learning strategies for analytics success. From predictive modeling to explainable AI, unlock key insights for your projects.

By Sisense Team May 30, 2023

Medians in SQL

Finding the min, max, and avg price of an order in your purchases table is easy. But what about the median price? Medians are much more difficult for the database to compute, so there usually isn’t a built-in function like…

pd blog featured selecting one row per group

By Sisense Team May 24, 2023

Selecting only one row per group

Selecting the First Row for each Group Sometimes you just want to graph the winners. Were there more iOS or Android users today? Grouping and counting the daily usage per platform is easy, but getting only the top platform for…

By Sisense Team May 18, 2023

How to calculate cohort retention in SQL

SQL is one of the analyst’s most powerful tools. In SQL Superstar, we give you actionable advice to help you get the most out of this versatile language and create beautiful, effective queries. Losing users sucks. Losing customers really sucks. If…

By Sisense Team May 12, 2023

Hashing tables to ensure consistency in Postgres, Redshift and MySQL

Maintaining cache consistency Maintaining a data cache optimized to serve different queries can help speed them up, and benefits from economies of scale. Maintaining this cache leads us to a critical question: How do I know if the cache is…

By Sisense Team May 8, 2023

How to format numbers as currency in Postgres, MySQL and Redshift

The all-important revenue graph In your venerable orders table, you’re almost certainly storing prices as numbers. Perhaps they’re integer, perhaps they’re numeric, perhaps you’re using Postgres and they’re money, or perhaps you rolled the dice on floating-point rounding errors and…

pd blog featured generate series redshift mysql min1

By Sisense Team May 2, 2023

Generate series in Redshift and MySQL

A lot of charts and tables are time series, and the queries behind them are often easier when you can join and aggregate against a list of dates. Not having a complete list of dates causes gaps in the results,…

By Sisense Team April 26, 2023

How to calculate confidence intervals in SQL

Statistical overconfidence: Dangerous and easy Imagine you have a small online business. This month 200 users signed up on your website, and 10 of them bought your $800 service. Great! You’ve made $8k of income. How much should you expect…

By Sisense Team April 20, 2023

2X your redshift speed with sortkeys and distkeys

The new guy in Town Like a lot of folks in the data community, we’ve been impressed with Redshift, Amazon’s new distributed database. Yet at first, we couldn’t figure out why performance was so variable on seemingly-simple queries. The key…

pd blog featured use subqueries to count 50x min

By Sisense Team April 14, 2023

Use subqueries to count distinct 50X faster

NB: These techniques are universal, but for syntax we chose Postgres. Thanks to the inimitable pgAdminIII for the Explain graphics. So useful, yet so slow Count distinct is the bane of SQL analysts, so it was an obvious choice for…