SQL Performance

FEBRUARY 22, 2021

I would like to share a couple of recent examples that help illustrate how using deprecated SQL Server features continues to bite us. The system table sys.sysprocesses was replaced way back in SQL Server 2005 by a set of dynamic management views (DMVs), most notably sys.dm_exec_requests , sys.dm_exec_sessions , and sys.dm_exec_connections.

Latency 57

Latency Servers Monitoring Systems 57

SQL Performance

APRIL 8, 2019

These AMD EPYC processors have a number of advantages for SQL Server workloads, as I will explain in this article. This 14nm first-generation AMD EPYC 7551 processor has 32 cores and 64 threads, and it works in one or two-socket servers. Both of these Intel processors are special bespoke models that are not in the Intel ARK database.

Azure 42

Azure Virtualization Storage Benchmarking 42

Brendan Gregg

NOVEMBER 29, 2017

In this configuration, the AMI and boot is paravirt (PV), the kernel is making hypercalls instead of privileged instructions, and the system is using paravirt network and storage drivers. It's all a bit confusing, and I wrote about this in 2014: [Xen Modes]. AWS has a name for their Bare Metal platform: it's the "Nitro system".

Virtualization 111

Virtualization AWS Hardware Storage 111

SQL Performance

OCTOBER 29, 2019

There are multiple methods to look at poorly performing queries in SQL Server, notably Query Store, Extended Events, and dynamic management views (DMVs). In order to use Query Store and Extended Events, you have to configure them in advance – either enabling Query Store for your database(s), or setting up an XE session and starting it.

C++ 74

C++ Database Servers Tuning 74

Brendan Gregg

SEPTEMBER 25, 2021

These strange questions came to the fore back in 2014 when Netflix was switching services from CentOS Linux to Ubuntu, and I helped debug several weird performance issues including one I'll describe here. A Cassandra database cluster had switched to Ubuntu and noticed write latency increased by over 30%. How would you time time?

Speed 52

Speed Java AWS Virtualization 52

Brendan Gregg

SEPTEMBER 25, 2021

These strange questions came to the fore back in 2014 when Netflix was switching services from CentOS Linux to Ubuntu, and I helped debug several weird performance issues including one I'll describe here. A Cassandra database cluster had switched to Ubuntu and noticed write latency increased by over 30%. How would you _time_ time?

Speed 40

Speed Java AWS Virtualization 40

The Morning Paper

AUGUST 27, 2019

I am so pleased to see a database systems paper addressing the concerns of the application developer! To the developer, a strongly consistent system behaves exactly like a single-threaded system running on a single node, so reasoning about the behaviour of the system is simple 1. VLDB’19.

Programming 59

Programming Processing Database Systems 59

SQL Server According to Bob

JUNE 3, 2016

SQL Server 2016 changes the internal design to (CheckScanner), applying no lock semantics and a design similar to those used with In-Memory Optimized (Hekaton) objects, allowing DBCC operations to scale far better than previous releases. The following chart shows the same 1TB database testing. SQL Server. SQL Server 2014.

Hardware 40

Hardware Cache Servers Software Engineering 40

SQL Performance

MAY 7, 2019

Back in 2014, I started a series of blog posts here to talk about specific wait types and what they do and don’t mean. I’m going to introduce you to wait statistics and explain how critical they are for troubleshooting workload performance in SQL Server. SQL Server also keeps track of how long the thread has to wait. Scheduling.

Servers 40

Servers Azure Metrics Tuning 40

Scalegrid

AUGUST 15, 2019

In 2014, we discussed 4 of the top MongoDB GUIs: MongoVue, MongoHub, RockMongo, and Robo 3T (formerly Robomongo), and again in 2016: MongoDB Compass, Robo 3T, Studio 3T, and MongoBooster. Should have an excellent way to measure server and query performance. Import data from RDBMS like MySQL, PostgreSQL, and SQL Server.

Database 40

Database Servers Monitoring Availability 40

Brendan Gregg

NOVEMBER 28, 2017

In this configuration, the AMI and boot is paravirt (PV), the kernel is making hypercalls instead of privileged instructions, and the system is using paravirt network and storage drivers. It's all a bit confusing, and I wrote about this in 2014: [Xen Modes]. AWS has a name for their Bare Metal platform: it's the "Nitro system".

Virtualization 40

Virtualization AWS Hardware Storage 40

SQL Performance

APRIL 23, 2019

In SQL Server 2012, grouped (vector) aggregation was able to use parallel batch-mode execution, but only for the partial (per-thread) aggregate. SQL Server 2014 added the ability to perform parallel batch-mode grouped aggregation within a single Hash Match Aggregate operator. Introduction. instructions are available.

Servers 67

Servers Testing Metrics Storage 67

Alex Russell

MARCH 6, 2021

Devices and networks have evolved too: Alex Russell @slightlylate An update on mobile CPUs and the Performance Inequality Gap: Mid-tier Android devices (~$300) now get the single-core performance of a 2014 iPhone and the multi-core perf of a 2015 iPhone. mid-priced Androids were slightly faster than 2014's iPhone 6.

Performance 124

Performance Network Cache Metrics 124

All Things Distributed

APRIL 4, 2017

In 2014 and 2015 respectively, AWS opened offices in Stockholm and Espoo, Finland. After migrating, database queries that took six seconds now take three seconds in their AWS infrastructure. This has led us to steadily increase our investment in the Nordics to serve our growing base of enterprise, public sector, and startup customers.

AWS 117

AWS Airlines Latency Games 117

O'Reilly

JULY 25, 2023

To provide some coherence to the music, I decided to use Taylor Swift songs since her discography covers the time span of most papers that I typically read: Her main albums were released in 2006, 2008, 2010, 2012, 2014, 2017, 2019, 2020, and 2022. This choice also inspired me to call my project Swift Papers.

Programming 98

Programming Code Design Benchmarking 98