Introduction
High-concurrency systems always look impressive on paper. You throw in dozens of CPU cores, crank up memory, design a schema with lightweight inserts, and proudly tell yourself, “This thing is going to fly.” And to be fair, under low load it probably does. A single session inserting rows into a simple table barely makes SQL Server break a sweat.
But the story changes once you start pushing that system with hundreds of parallel inserts. Suddenly, all that horsepower doesn’t matter anymore, because every thread is fighting over the same tiny spot in memory: the last page of a clustered