Kalen Delaney

Kalen Delaney has been working with SQL Server since 1987, and provides advanced SQL Server training to clients worldwide. She has been a SQL Server MVP since 1993 and has been writing about SQL Server almost as long. Kalen has spoken at dozens of technical conferences, including almost every PASS conference in the US since the organization’s founding in 1999. Kalen is the author or co-author of many books on SQL Server, including SQL Server 2012 Internals, from Microsoft Press. She is one of the main editors for SQL Server Central’s SQL Server Stairways Series. Kalen blogs at www.sqlblog.com and her personal website and schedule can be found at www.SQLServerInternals.com.

Kalen Delaney 07 December 2017

SQL Server Internals: In-Memory OLTP

SQL Books

In this book Kalen Delaney introduces and explains how the 2016 In-Memory OLTP engine works. The Hekaton internals knowledge offered in this book will help you migrate existing tables or databases to Hekaton, and get faster performance from your SQL Server applications than you ever thought possible.… Read more

SQL Books

Kalen Delaney 22 October 2014

Hekaton in 1000 Words

Database Administration

The SQL Server 2014 In-Memory OLTP engine (a.k.a. Hekaton) is a radical change for relational databases. This article, an exerpt from Kalen Delaney's book "SQL Server Internals: In-Memory OLTP", provides a brief overview of what Hekaton is and why it's important.… Read more

Database Administration

Kalen Delaney 05 June 2014

Row Versioning Concurrency in SQL Server

T-SQL Programming

The optimistic concurrency model assumes that several concurrent transactions can usually complete without interfering with each other, and therefore do not require draconian locking on the resources they access. SQL Server 2005, and later, implements a form of this model called row versioning concurrency. It works by remembering the value of the data at the start of the transaction and checking that no other transaction has modified it before committing. If this optimism is justified for the pattern of activity within a database, it can improve performance by greatly reducing blocking. Kalen Delaney explains how it works in SQL Server. … Read more

T-SQL Programming

Kalen Delaney 02 October 2012

SQL Server Concurrency: Locking, Blocking and Row Versioning

SQL Books

Your application can have impeachable indexes and queries, but they won't help you if you can't get to your data because another application has it locked. That's why every DBA and developer must understand SQL Server concurrency and how to troubleshoot excessive blocking or deadlocking. Kalen Delaney's book is your guide.… Read more

SQL Books