Simon Liew

Simon Liew

Simon Liew

Simon Liew an independent SQL Server Consultant with deep understanding of Microsoft SQL Server technology with focus on delivering business solutions. He loves exploring data and passionate about sharing his knowledge.

Simon has over 15+ years of database design, implementation, administration and development in SQL Server. He is a Microsoft Certified Master for SQL Server 2008 and holds a Master’s Degree in Distributed Computing. Achieving Microsoft masters-level certifications validate the deepest level of product expertise, as well as the ability to design and build the most innovative solutions for complex on-premises, off-premises, and hybrid enterprise environments using Microsoft technologies.

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Simon Liew

SQL Server Logins, Users and Security Identifiers (SIDs)

July 12, 2017 by

Abstract

Logins and Users are basic security concepts in SQL Server. They are often, and incorrectly, considered to be pretty much one in the same so it is sometimes confusing to some SQL Server users. Another important security concept tied to a login and user in SQL Server is Security Identifiers (SID). This article will explain these concepts through a step-by-step demonstration. This article will focus on the Windows login and provide some specific usage scenarios.

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The impact of Residual Predicates in a SQL Server Index Seek operation

March 6, 2017 by

Abstract

It is common assumption that an Index Seek operation in a query plan is optimal when returning a low number of output rows. In a scenario involving residual predicates, an Index Seek operation could be reading a lot more rows than it needs into the memory, then each row is evaluated and discarded in memory based on the residual predicate and returns low number of output rows.

This article will explain the concept and the impact of Residual Predicates in a SQL Server Index Seek operation.

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