You always wanted to know how to pass arrays to SQL Server? Watch this Ultimate Guide to Table-Valued Parameters! Hello and welcome! My name is Vedran Kesegić and this video is an absolute “must” for database developers. Fast performing database …
How to pass arrays to SQL? TVP – The Ultimate Guide Read more »
OUTER APPLY(SELECT TOP 1) pattern is widespread, even baked into some frameworks like Entity Framework. But is it a good practice? This demo will show. Based on a real-world optimization problem and solved with great success. The demo shows it …
Did you know that SUM() aggregate can be used together with OVER() clause? A short intro to windowing functions:
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SELECT SUM(Amount) OVER() -- What!? FROM dbo.PersonCityAmount |
The result is graphically visualized by using only SQL Server Management Studio and unicode characters:
Introduction If you are in search for a good ORM, keep reading. Alan Hyneman, the author of SQLPlus.net was very kind to give an interview and answer tough questions that a developer might ask. Feel free to ask more in …
When multiple sessions insert into the same table, and something unique is there (uq index, uq constraint), a “duplicate key” error (2601, 2627) occurs from time to time, almost inevitable. If your app is affected with intermittent “duplicate key” surprises, …
While ago I wrote SSMS Addin called SQL XDetails. It was not updated long time because GUI integration with new SSMS versions were different every time and too much for my poor csharp knowledge. I am a DB guy after …
Your SQL Server may be slow for a peculiar reason: a run-away query that pushes-out all other queries from the plan cache, like a huge wave. So called “tsunami query”. Tsunami query wipes other plans from the cache and makes your SQL running slow. Creating tsunami query is easy and usually not intentional: a developer concatenates values in SQL command string. As it “works on my machine”, it easily slips to production (nobody tests for this, right?), and the monster is loose!
Introduction You developed a new TSQL code and want to check is there a slow SQL statement inside and which is it? Or you debug the code and want to know which statement throws error, maybe inside of a trigger …
Do you use ROWVERSION/TIMESTAMP to pull changed data? If you do, you might experience a problem – not all changed rows are pulled, some are skipped. How can that be, if we pulled entire range of rowverion changes with no …
Introduction Demonstration of the smallest possible deadlock: only one statement, one table, one row. Without transactions (no BEGIN TRANSACTION). Even RCSI (Read Committed Snapshot Isolation) is turned ON to eliminate shared locks. Everything is “by the book” as Books Online …
