CSS SQL Server Engineers

This is the official team Web Log for Microsoft Customer Service and Support (CSS) SQL Support. Posts are provided by the CSS SQL Escalation Services team.

Understanding Optimizer Timeout and how Complex queries can be Affected in SQL Server

What Is Optimizer Timeout? SQL Server uses a cost-based query optimizer. Therefore, it selects a...

Author: Joseph.Pilov Date: 10/19/2018

AGLatency report tool V2.2 introduction

I wrote an article to discuss about data movement latency between AG groups:...

Author: SimonSu Date: 09/08/2018

July 10, 2018 Windows updates cause SQL startup issues due to "TCP port is already in use" errors

We have recently become aware of a regression in one of the TCP/IP functions that manages the TCP...

Author: Jordon Riel Date: 07/26/2018

Lesson learned from an Availability Group performance case

Writer: Simon Su Technical Reviewer: Pam Lahoud, Sourabh Agarwal, Tejas Shah  Problem description...

Author: SimonSu Date: 04/05/2018

Troubleshooting SQL Server Scheduling and Yielding

Writer: Simon Su Technical Reviewer: Pam Lahoud, Sourabh Agarwal, Tejas Shah    Scheduling and...

Author: SimonSu Date: 04/05/2018

Troubleshooting data movement latency between synchronous-commit AlwaysOn Availability Groups

Writer: Simon Su Technical Reviewer: Pam Lahoud, Sourabh Agarwal, Tejas Shah Applies to: SQL Server...

Author: SimonSu Date: 04/05/2018

Installation of SQL Server 2017 failing with 'VS Shell installation has failed with exit code 1638'

Dear all, Depending on which products were installed on the server beforehand, a SQL Server 2017...

Author: Guillaume Fourrat [MSFT] Date: 03/26/2018

Uniqueifier considerations and error 666

This post is intended to shed some light around uniqueifiers and table design that rely on its...

Author: Luciano Moreira Date: 02/16/2018

SQL Setup ToolSuite Introduction (3) – SQL Registry Viewer Version 2.2

You may want to know what registry keys will be added to system for a SQL server installation. If...

Author: SimonSu Date: 01/24/2018

SQL Setup ToolSuite Introduction (2) – Product Browser

Oftentimes when I worked on a setup case I hope I have a simple tool to tell me the detailed...

Author: SimonSu Date: 01/24/2018

SQL Setup ToolSuite Introduction (1) –FixMissingMSI

If you have encountered missing cached MSI/MSP issues during SQL server setup, you may have knew...

Author: SimonSu Date: 01/24/2018

Changes to hashing algorithm for self-signed certificate in SQL Server 2017

Starting with SQL Server 2005, a self-signed certificate is created automatically during the startup...

Author: Venu Cherukupalli Date: 11/08/2017

How to safeguard SQL Server on Linux from OOM-Killer

On a Windows based server, when all the available memory including the page file is consumed, the...

Author: Venu Cherukupalli Date: 10/17/2017

New season, New software, New servicing model

Greetings. It feels like a lot of change is in the air! Last Friday marked the Autumnal equinox....

Author: psssql Date: 09/29/2017

SQL Nexus 6.0 is released to github

With codeplex shutting down, we have moved SQL Nexus to github with a new release (6.0). Now both...

Author: JackLi Date: 07/26/2017

SQL Server : large RAM and DB Checkpointing

SQL Server : large RAM and DB Checkpointing Hi everyone, This post’s purpose is to establish a...

Author: Guillaume Fourrat [MSFT] Date: 06/29/2017

You may see “out of user memory quota” message in errorlog when you use In-Memory OLTP feature

Recently we got an inquiry from a customer who received the following message in errorlog and wanted...

Author: JackLi Date: 06/07/2017

Unable to issue alter table for a memory optimized tables

Recently I assisted on a customer issue where customer wasn’t able to alter a memory optimized table...

Author: JackLi Date: 05/10/2017

Memory optimized table variable and cardinality estimate

In a previous blog, I talked about memory optimized table consumes memory until end of the batch. In...

Author: JackLi Date: 05/10/2017

Unable to restore a backup - Msg 3241

I worked on an interesting issue today where a user couldn’t restore a backup. Here is what this...

Author: JackLi Date: 04/12/2017

Why am I getting so many checkpoint files when I have In-Memory OLTP enabled?

Recently, I looked an In-Memory OLTP issue with Principal Software Engineer Bob Dorr who is still my...

Author: JackLi Date: 03/06/2017

A few new things in XML plan to help you troubleshoot query performance

In this blog Added per-operator level performance stats for Query Processing, Senior PM in QP talks...

Author: JackLi Date: 02/28/2017

Be aware of 701 error if you use memory optimized table variable in a loop

In blog “Importance of choosing correct bucket count of hash indexes on a memory optimized table”, I...

Author: JackLi Date: 02/22/2017

Importance of choosing correct bucket count of hash indexes on a memory optimized table

I was working with a customer to troubleshoot memory optimized table issues. In this scenario, our...

Author: JackLi Date: 02/18/2017

Solving SQL Connectivity issues: A new guided walk through just got published

We recently published a new document that provides a one stop shop for solving majority of...

Author: Ramu_MSFT Date: 01/29/2017

Pssdiag & Sqldiag Manager update

We are releasing a new version of Pssdiag & Sqldiag Manager which supports SQL Server 2016. It...

Author: JackLi Date: 01/12/2017

Why can’t I get a parallel plan when rebuilding my index?

In support, we frequently have customers who call us and want to find out why a particular query...

Author: JackLi Date: 01/09/2017

Unable to connect to SQL Server AlwaysOn Listener on Azure due to misconfigured subnet mask

When it comes to troubleshooting, the more you know the better troubleshooter you are (in my...

Author: JackLi Date: 12/04/2016

SQL Nexus 5.5.0.1 was released

We just released SQL Nexus 5.5.0.1 on codeplex. In addition to numerous ‘rules’ that catch issues...

Author: JackLi Date: 11/20/2016

Unable to drop a user in a database

A user called in for help because he wasn’t able to drop a user from a database. The error message...

Author: JackLi Date: 11/15/2016

Backup to remote Azure URL failed due to throttling at VM level

There are multiple levels of throttling with Azure.  You can get throttled at disk level, storage...

Author: JackLi Date: 10/25/2016

SQL 2016 -- Why can’t I STRETCH my database (I have the right user name and password)?

Recently we got a call from customer who was trying to enable stretch database but repeatedly got...

Author: JackLi Date: 10/18/2016

Default auto statistics update threshold change for SQL Server 2016

Lately, we had a customer who contacted us for a performance issue where their server performed much...

Author: JackLi Date: 10/04/2016

Proxy settings & backup to URL (Azure blob storage)

With so many users new to Azure, Sometimes an issue appears more complex than it really is. If you...

Author: JackLi Date: 09/29/2016

Why “SQL Server Configuration” section on my Azure Virtual Machine is not available?

If you created an SQL Server VM via azure portal, there will be a section called “SQL Server...

Author: JackLi Date: 09/28/2016

Unable to connect to SQL Server on azure VM due to an extra NSG applied to subnet

If you need to open up your SQL Server on an Azure VM to public internet access, you need to look no...

Author: JackLi Date: 09/18/2016

Why am I getting NULL values for query_plan from sys.dm_exec_query_plan?

Recently we got a customer who called in and wanted to know why he received NULL for query_plan when...

Author: JackLi Date: 07/13/2016

Why do I get the infrastructure error for login failures?

In the past few weeks, I saw this error come across quite a bit and thought I will provide an...

Author: psssql Date: 07/09/2016

Tips & Tricks on ‘cloning’ Azure SQL virtual machines from captured images

While we have documentation on how to create a VM from captured image under “How to capture a...

Author: JackLi Date: 07/06/2016

New memory grant query hint MIN_GRANT_PERCENT came to rescue

In SQL Server 2012 SP3, we made supportability improvements in the memory grant space. One of the...

Author: JackLi Date: 06/09/2016

Bob is Moving To BOBSQL

Bob Ward and Bob Dorr are among the founding members of PSSSQL as long standing SQL Server support...

Author: psssql Date: 06/07/2016

SQL 2016 - It Just Runs Faster: XEvent Linq Reader

SQL Server 2016 improves the XEvent Linq reader scalability and performance. The XEvent UI in SQL...

Author: psssql Date: 05/18/2016

SQL 2016 - Leverages On Demand MSDTC Startup

SQL Server leverages MSDTC for distributed transactions (begin distributed transaction, remote proc...

Author: psssql Date: 05/12/2016

SQL 2016 - It Just Runs Faster: In-Memory Optimized Database Worker Pool

SQL Server leverages a worker pool for the In-Memory Optimized Database capabilities. Prior to SQL...

Author: psssql Date: 05/10/2016

SQL 2016 - It Just Runs Faster - AlwaysOn AES-NI Encryption

The SQL Server 2016, AlwaysOn, log transport takes advantage of hardware based encryption to...

Author: psssql Date: 05/05/2016

SQL 2016 - It Just Runs Faster: AlwaysOn Parallel Compression / Improved Algorithms

SQL Server 2016 introduces two distinct changes in the AlwaysOn transport, compression design....

Author: psssql Date: 05/03/2016

SQL 2016 - It Just Runs Faster: AlwaysOn Log Transport Reduced Context Switches

The AlwaysOn log transport uses a SQL Broker-like based design to send and receive messages between...

Author: psssql Date: 04/28/2016

SQL 2016 - It Just Runs Faster - BULK INSERT Uses Vector Instructions (SSE/AVX)

SQL Server 2016 enhanced the bulk insert activities (BULK INSERT), leveraging the CPUs vector...

Author: psssql Date: 04/27/2016

SQL 2016 - It Just Runs Faster: Column Store Uses Vector Instructions (SSE/AVX)

SQL Server's Column Store feature is designed to accommodate large amounts of data and associated...

Author: psssql Date: 04/22/2016

Why do we see ENCRYPTION_SCAN locks in a SQL server

Recently I worked with a customer who noticed that several sessions[spid’s] in their SQL Server was...

Author: psssql Date: 04/19/2016

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