Transparent Data Encryption and Always Encrypted

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If you need to store confidential data in your database, you can use data encryption. SQL Server supports encryption with symmetric keys, asymmetric keys, certificates, and password phrases. I assume that you, the reader, are already familiar with these terms. In this article, I will focus on two out of many encryption options provided by SQL Server:

  • Transparent Data Encryption (TDE)
  • Always Encrypted (AE)

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What Can Query Plan Tell?

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Introduction

SQL query describes the expected result, not the way to get the result. The set of specific steps the server must take to return the result is called the query execution plan. The plan is built by the optimizer. Selection of a plan affects execution speed, what makes it one of the most important elements of the query performance problem analysis.

Execution plan comprises operators and their properties that are interrelated with each other in the form of the tree structure. Each operator is responsible for a separate logical or physical operation. All together, they ensure the result described in the query text. Inside the tree, operators are represented by the class objects in the memory of SQL Server. Server users (that is, you and me) see the description generated in XML format with a specific schema, that is displayed graphically by the SQL Server Management Studio (SSMS) environment.

There are many various plan operators and even more properties. Besides, new ones emerge from time to time. This article does not dare to describe all possible variety of operators. Instead, I would like to share the most interesting additions in this subject and to remind some old but useful elements. Read More

Troubleshooting long running queries in MS SQL Server

Troubleshooting long running queries in MS SQL Server
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Preface

There is an information system that I administer. The system consists of the following components:

1. MS SQL Server database
2. Server application
3. Client applications

These information systems are installed on several objects. The information system is used actively 24 hours a day by 2 to 20 users at once on each object. Therefore, you cannot perform routine maintenance all at once. So, I have to «spread» SQL Server index defragmentation throughout the day, rather than defragmenting all the necessary fragmented indexes at one stroke. This applies to other operations as well.

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