In this article we explore schema evolution capabilities and limitations in Databricks with regular parquet format and explore schema evolution features and capabilities through delta format with inserts, appends, and overwrites.
Introduction In my last article, An Introduction to Azure Data Explorer, I discussed the process of creating and using Azure Data Explorer. Azure Data Explorer is mainly used for storing and running interactive analytics on Big Data. First, I need to create the ADX cluster. Then, one or more databases should be created inside the […]
The three themes for speakers at this year's PASS Data Community Summit are: Back to Basics, Reach for the Clouds, and Level Up. The goal here is content that covers a wide variety of areas, with many fewer restrictions from previous years. Perhaps the big thing to note for this year's event is: Free. That's […]
In this article we cover what a Common Table Expression CTE is and how to write a CTE for doing selects, inserts, deletes, updates and more.
Director at ThoughtWorks Pramod Sadalage explores trends such as rapid digital transformation and an ever-changing tech landscape, that'll change the way we work with databases and DevOps in the next 20 years.
Tesla is updating their software in a real world, real life DevOps that their customers experience every day. It impresses Steve and tempts him to get one of their cars.
This article examines how to split a data set for training and testing and evaluating our model using Python.
How to create and maintain a 'data dictionary' for your databases, in JSON format, which you can then use to add and update the table descriptions, whenever you build a new version using Flyway.
Using sequences when scaling up with Oracle RAC presents more issues with contention. In this article, Jonathan Lewis explains how to avoid the problems.
It's a holiday weekend in the US this weekend. As such, many of you will be taking a break from work and enjoying time with family, as well as remembering some history in the US. If you're in the rest of the world, hopefully you have a holiday coming up soon you can enjoy. One […]
By ReviewMyDB
Index maintenance has always meant nightly jobs and a window you have to defend....
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By Steve Jones
One of the things I’ve been requesting for a number of years is cost...
Comments posted to this topic are about the item SQL Art, Part 4: Happy...
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I have this data in the dbo.Commission table in a SQL Server 2022 database.
salesperson commission Brian 12 Brian 16 Andy 7 Andy 14 Andy 21 Steve 20 Steve NULLAll the data is a varchar, and I decide to run this query to get the totals for each salesperson.
SELECT SalesPerson
, AVG(TRY_PARSE(Commission AS int)) AS TotalCommission
FROM commission
GROUP BY SalesPerson
GO
What average commission is calculated for Steve? See possible answers