A plain join quietly hides every column nobody described. See the LEFT JOIN that keeps them, and turn the gaps into a to-do list.
Out-of-Row Storage for varchar(max): Keeping Data Pages Small
Turn on the out-of-row option and nothing happens until you rewrite the data. I measure pages and reads at each step so you can see the real trade.
FOR JSON Data Types: How bit, Dates and Money Come Out
Your API returns 1 and the client wanted true. Here is how FOR JSON picks a JSON type for bit, dates, decimal, money, binary and NULL, and how to fix it.
Interview Question of the Week #022: How to Get Started with Big Data?
When an interviewer asks how you would get started with big data, a list of tools is the weakest answer. This post gives a short model answer: start from SQL, learn the core ideas, run one engine on a laptop and build one small project end to end.
Big Data Upgraded: The 2013 Series Rewritten for Today
Big Data Upgraded is the reading path for 23 articles, most of them first written in 2013, now rewritten for today’s tools. Most new platforms now build on Spark, Parquet, open table formats and change data capture. Here is the whole set in reading order, with one line on each.
Batch vs Stream Processing: When Data Cannot Wait
Batch vs Stream Processing is a choice about how long an answer can wait. This post compares an hourly batch job with a 5-minute stream window on the same six orders, covers the cost of real time and shows how to choose.
What a Data Scientist Does: The Skills That Still Matter
What a data scientist does is turn a vague question into an answer that people can trust and act on. This post walks through the work as a loop, and shows the summary statistics step in T-SQL on a small bike rental log.