Slava Oks's WebLog

What made Porting Microsoft SQL Server to Linux to be the right move after all

It has taken us a little more than two and a half years to bring an official version of SQL Server...

Author: SlavaO Date: 09/24/2017

SQL Server on Linux, aka project Helsinki: Story behind the idea

As I mentioned in my previous post, I left SQL Server in 2007 to work on what ended up being a super...

Author: SlavaO Date: 12/20/2016

One, Two, Three... Boom!

...I am back and getting ready to start blogging. It has been almost ten years since my last blog...

Author: SlavaO Date: 12/20/2016

Changing gears

You haven't heard from me in while and there is a reason. I moved from SQL Server's Storage Engine...

Author: slavao Date: 03/07/2007

Q and A: Ratio between AWE Allocated and VM Committed/Reserved in DBCC MEMORYSTATUS output

Q: What kind of ratio should you expect to see between AWE Allocated and VM Committed/Reserved? We...

Author: slavao Date: 01/02/2007

Q & A: I am running on 64 bit and all of my tasks are waiting on SOS_RESERVEDMEMBLOCKLIST, What is going on?

This wait type represents waiting on multi page allocations inside of SQLOS's memory manager. As you...

Author: slavao Date: 11/14/2006

SQLOSDMV's Continue

sys.dm_os_waiting_tasks One can run lots of interesting queries using this view. You can even use...

Author: slavao Date: 11/14/2006

Q & A: Does SQL Server always respond to memory pressure?

Q: I thought I've seen reference recently to problems with SQL2005 not releasing memory when under...

Author: slavao Date: 11/13/2006

SQLOS's DMVs Continue

sys.dm_os_schedulers Q. Do I need to by more CPUs? In order to answer this question you have to find...

Author: slavao Date: 09/28/2006

SQLOS's DMVs

SQL Server 2005 has a large number of DMVs that you can take advantage of especially when you try to...

Author: slavao Date: 08/22/2006

Talking points around SQL Server 2005 scalability

Couple of weeks ago I did a talk on SQL Server 2005 scalability. The actual talk was not about the...

Author: slavao Date: 08/03/2006

Q & A: I can't make SQL Server 2005 32 bit version to use all memory on the machine

I’m currently using the RTM+SP1 x86-SQL2005 build on a server which has 32GB of physical memory. I...

Author: slavao Date: 08/03/2006

Set of new features in SQL Server 2005 enabled by SQLOS

Couple of weeks ago I had a chance to visit set of our customers and talk to them directly. It was...

Author: slavao Date: 04/12/2006

Q and A: Enabling AWE settings for SQL Server 32 bit edition in WOW

Q. A customer wants to run SQL 2000 SP4 in a Windows Server 2003 SP1 x64 edition. They did the...

Author: slavao Date: 04/12/2006

Q and A: Some questions about output from dbcc memorystatus

Recently I have recieved following question: A customer of mine is getting this output on an Itanium...

Author: slavao Date: 03/19/2006

Q and A: SQL Server memory allocated outside of Buffer Pool, formerly known as MemToLeave

Q. Under SQL Server 2000 Is the memtoleave concept still valid under 64-bit? A. Yes. If SQL Server’s...

Author: slavao Date: 03/14/2006

Q and A: Do I need to run "sp_configure 'awe enabled', 1" to make 64 bit version of SQL Server use locked pages?

The answer is No. The source of possible confusion came from one of my previous posts:...

Author: slavao Date: 03/13/2006

Be Aware: 4GB of VAS under WOW, does it really worth it?

By now you have heard a lot about the fact that under WOW a 32 bit process can get 4GB of VAS. I...

Author: slavao Date: 03/12/2006

Retrieving information about CPUs' relationships

In order for server side applications to run efficiently on modern hardware they have to understand...

Author: slavao Date: 03/12/2006

Q and A: Clock Hands - what are they for?

Q1 I read in your blog about the new algorithm with two clock hands to control memory consumption,...

Author: slavao Date: 11/20/2005

Q and A: Virtual Address Space, VAS, reservation - why bother?

Seems like today is a question day :-). I will attempt to answer several questions about VAS I got...

Author: slavao Date: 11/15/2005

Q and A: x64 & AWE mechanism

Today I received following question: Hello, We will be running Windows Server 2003 x64 with SQL...

Author: slavao Date: 11/15/2005

Be aware: To Hyper or not to Hyper

Our customers observed very interesting behavior on high end Hyperthreading (HT) enabled hardware....

Author: slavao Date: 11/12/2005

Final changes in SQL Server 2005's memory manager

As you would expect in the last several months SQL 2005 went through rigorous testing. During the...

Author: slavao Date: 11/05/2005

Q and A: Using Lock Pages In memory on 64 bit platform

Q: Hello Slava, I would like to confirm my understanding that on SQL 2005 64 bit edition it is...

Author: slavao Date: 08/31/2005

Talking Points around Memory Manager in SQL Server 2005

Yesterday I gave a talk around SQL Server 2005's memory manager. The talk was rather chalk talk. It...

Author: slavao Date: 08/30/2005

Configuring SQL Server 2005 for Soft NUMA

Sometimes I am surprised how issues come up the moment you mention them J. Recently, I have...

Author: slavao Date: 08/18/2005

SQL Server 2005 NUMA support & troubleshooting

SQL Server 2005 has been designed to take advantage of NUMA features exposed by both hardware and...

Author: slavao Date: 08/02/2005

SQLOS helps SQL Server to leverage hardware capabilities

I just finished an article on how SQLOS helps SQL Server to leverage hardware capabilities...

Author: slavao Date: 07/20/2005

Platform layer for SQL Server:

A new platform layer in SQL Server 2005 to exploit new hardware capabilities and their trends Slava...

Author: slavao Date: 07/20/2005

Be Aware: VirtualAlloc with MEM_RESERVE can fail even if you have plenty of VAS inside of the process

Many developers assume that if you have plenty of free VAS in your process VirtualAlloc...

Author: slavao Date: 06/03/2005

Q and A: Controlling size of a single cache in SQL 2005

Q: I have teaching a class on Yukon for the Ascend program, and the class had a question I wanted to...

Author: slavao Date: 06/03/2005

Q and A: Max memory with sql server 2000 / win2003 x64

Today, I received following question Q: Slava,I have a question for you. Sql 2000 is documented to...

Author: slavao Date: 06/03/2005

Be Aware: Using AWE, locked pages in memory, on 64 bit

We have already talked about Windows AWE mechanism on 32 bit and how SQL Server utilizes it. Today I...

Author: slavao Date: 04/29/2005

Be Aware: IA64 Stack Size

Stack subject in Windows OS is fascinating. There are so many interesting technical problems...

Author: slavao Date: 03/19/2005

SQLOS Caching

Yukon caching vs SQL2000 What makes Yukon memory management different from SQL2000 is elaborative...

Author: slavao Date: 03/18/2005

Be aware: FLS-Fiber Local Storage

Problem: In the last several months there were several publications describing usage of fibers. When...

Author: slavao Date: 02/28/2005

Be aware: a new section in my blog

Periodically, I bump into unusual behavior, features, of compiler, operating system, strange design...

Author: slavao Date: 02/22/2005

SQLOS's memory manager: responding to memory pressure

Resource Monitor and Memory Pressure When configuring SQL Server it is very important to understand...

Author: slavao Date: 02/19/2005

Changes in dbcc memorystatus in Yukon

You probably have used dbcc memory status command in SQL2000. In Yukon we have changed output of...

Author: slavao Date: 02/14/2005

SQLOS's memory manager and SQL Server's Buffer Pool

SQLOS's memory manager consists of several components such as memory nodes, memory clerks, memory...

Author: slavao Date: 02/11/2005

SQLOS - unleashed

With SQL Server 2005 Beta 1 and Beta 2 you might have noticed that there is no ums.dll in the bin...

Author: slavao Date: 02/05/2005

Look at Memory Leaks - Classify and Identify

In my previous post I talked about type of Memory Pressures. Today I would like to talk about...

Author: slavao Date: 02/04/2005

Memory Pressure - Classified

So far I touched on subjects that have been widely discussed in the industry. Today I would like to...

Author: slavao Date: 02/01/2005

Getting an exception call stack from the catch block (C++)

This is my first post in this category so I am really looking forward to your comments :-) Today I...

Author: slavao Date: 01/30/2005

A look at Windows Virtual Memory mechanisms (continuation of "A look at Virtual Address Space - VAS")

As I promised last time here comes next post on memory J. Remember, my eventual goal is to reveal...

Author: slavao Date: 01/29/2005

Tracking VAS in Yukon, cont...

Some of you could have gotten bored with my previous post...

Author: slavao Date: 01/28/2005

A look at Virtual Address Space - VAS

Memory is a set of common resources shared by applications, their components and operating system....

Author: slavao Date: 01/27/2005

Tracking VAS in Yukon

When we started working on the next release of SQL Server, Yukon, we realized that supportability...

Author: slavao Date: 01/26/2005