SQL Performance

MARCH 30, 2021

The fundamentals of row mode parallel execution haven’t changed since SQL Server 2005, so the following discussion is broadly applicable. Running a parallel plan on a single thread can also happen when a cached parallel plan is reused by a session that is limited to DOP 1 by an environmental setting (e.g. MonthlyPosts AS. (

Cache 98

Cache Servers Processing Operating System 98

John McCalpin

APRIL 2, 2020

The presentation discusses a family of simple performance models that I developed over the last 20 years — originally in support of processor and system design at SGI (1996-1999), IBM (1999-2005), and AMD (2006-2008), but more recently in support of system procurements at The Texas Advanced Computing Center (TACC) (2009-present).

Benchmarking 59

Benchmarking Performance Latency Architecture 59

SQL Server According to Bob

JANUARY 11, 2020

KB sectors run on smaller sectors   14 System and sample databases   15 Determining the formatted sector size of database   15 What sector sizes does SQL Server support?

Servers 40

Servers Cache Database Media 40

SQL Server According to Bob

DECEMBER 18, 2018

Device level flushing may have an impact on your I/O caching, read ahead or other behaviors of the storage system. The “forced flush” changes in SQL Server avoid flushes, when possible, in order to improve performance on non-optimized Fua file systems. Linux open command flag used to bypass file system cache.

Servers 90

Servers Media Cache Storage 90