article thumbnail

SQL Server I/O Basics Chapter #2

SQL Server According to Bob

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
article thumbnail

SQL Server On Linux: Forced Unit Access (Fua) Internals

SQL Server According to Bob

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
Insiders

Sign Up for our Newsletter

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.

Trending Sources

article thumbnail

How Parallel Plans Start Up – Part 1

SQL Performance

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
article thumbnail

The Surprising Effectiveness of Non-Overlapping, Sensitivity-Based Performance Models

John McCalpin

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).