Introduction It was the week before Black Friday — the biggest online ad rush of the year. Our US-based ad-tech platform was gearing up for an insane traffic spike. Hundreds of real-time campaigns were about to go live across multiple brands, each with thousands of user sessions flowing through our system. Every incoming user impression […]
2025-07-22
2,424 reads
In this article, I wanted to test a common assumption we DBAs make – that adding INCLUDE columns to indexes is harmless. I created a FULL recovery test database with a realistic wide Orders table containing extra large VARCHAR columns to simulate an ERP workload. I ran updates and measured transaction log backup sizes before and after adding INCLUDE columns to a nonclustered index. The results shocked me. The update without INCLUDE columns generated a 10 MB log backup, while the same update with INCLUDE columns produced over 170 MB – a 17x increase in log volume. I explain why this happens: INCLUDE columns are physically stored in index leaf rows, so updates affecting them write bigger log records. I also clarify that updating key columns generates even more log than INCLUDE updates because it involves row movement (delete + insert), but INCLUDE updates still cost more log than if those columns weren’t indexed at all. The takeaway is clear – INCLUDE columns are powerful, but they silently increase transaction log generation, impacting backup sizes, replication lag, and DR readiness. Always measure their real cost before deploying to production.
2025-07-18
713 reads
This article dives deep into cxpacket and cxconsumer in sql server, explaining how to simulate each, when they appear, and why they matter. Using live execution plans, wait monitoring, and worker thread diagnostics, we uncover how uneven parallelism triggers thread sync waits—and how SQL Server sometimes hides real issues behind innocent-looking CXCONSUMER waits. Includes step-by-step queries, tuning tips, and a real-world scenario where repartition streams quietly ruined performance.
2025-07-07
4,051 reads
Misusing MAXDOP can silently kill performance across your SQL Server. In this deep dive, we uncover how one bad query caused CPU meltdown, run real-world tests, and show how tuning—not parallelism—often holds the true fix.
2025-06-23
4,578 reads
This article examines how tempdb is affected by recursive queries, using a few different methods.
2025-05-23
2,125 reads
Learn how to safely remove a SQL Server .ndf data file without any downtime using DBCC SHRINKFILE (EMPTYFILE). This hands-on tutorial walks through real-world Azure-based setup, data redistribution, and storage cleanup — ideal for DBAs managing enterprise SQL Server environments.
2025-05-16
2,782 reads
By Steve Jones
One of the things I’ve tried hard to do in database development situations if...
By DataOnWheels
The T-SQL Tuesday topic this month comes James Serra. What career risks have you...
This T-SQL Tuesday is hosted by the one and only James Serra – literally...
We have two "identical" instances of an ASP.NET web service (or so I have...
Comments posted to this topic are about the item OPENQUERY Flexibility
Comments posted to this topic are about the item A Full Shutdown
Which of these are valid OPENQUERY() uses?
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