Demo: Identify and fix plan change regression in SQL Server 2017 RC1

Plan change regression happens when SQL Database changes a plan for some T-SQL query, and the new plan has the worse performance than the previous one. SQL Server 2017 has Automatic Tuning feature that enables you to easily find plan change regressions and fix them. In this post you will see the demo script that you… Read more

What is plan regression in SQL Server?

Plan regression happens when SQL Server starts using the sub-optimal SQL plan to execute some T-SQL query. Usually you will see that some T-SQL query is executing really fast, but then it gets slower without any obvious reason. In this post you will see how can plan regression happen…. Read more

Use WITH clause in OPENJSON to improve parsing performance

OPENJSON function has a WITH clause where you can specify what fields should be extracted from input JSON. This might improve performance of your queries compared to the case where you use OPENJSON without schema and later extract information from the parsed JSON using JSON_VALUE function…. Read more

Automatic index management in Azure SQL database

Azure SQL Database has a built-in intelligence mechanism that can automatically tune and improve performance of your queries by dynamically adapting the database schema to your workload. In Azure SQL Database, you don’t need to worry about the index analysis and design, because Azure SQL Database learns about your workload and ensures that your data… Read more

“You Shall Not Regress!!!” – How SQL Server 2017 prevents plan regressions?

SQL plan regression is a case when a T-SQL query that executed fine becomes much slower or uses more resources because the underlying SQL plan changed. SQL Server 2017 would not allow that kind of regressions if you enable new automatic tuning feature on your database…. Read more

Comparing performance of data access libraries using StackExchange/Dapper benchmark

One of the most important questions that you need to answer in your projects is what data access library you should use to access your data in SQL Server database. One of the benchmarks that you can use is StackExchange Dapper benchmark that checks how fast could different data access libraries fetch a single row from… Read more

In-Memory OLTP Videos: What it is and When/How to use it

In-Memory OLTP is the premier technology for optimizing the performance of transaction processing in SQL Server. Last week at Microsoft Ignite 2016 we presented two session about the In-Memory OLTP technology in SQL Server and Azure SQL Database. For those of you who did not attend the conference or did not make it to the… Read more

In-Memory OLTP – what’s new in SQL2016 CTP3

We have been hard at work to add features to In-Memory OLTP to make it easier to build apps and to adopt In-Memory OLTP in existing apps, as well as to increase overall performance and scaling. Below is the list of In-Memory OLTP enhancements that we have released in SQL2016 thus far, up to and… Read more