Brendan Gregg

DECEMBER 21, 2019

For my AWS re:Invent talk on BPF Performance Analysis at Netflix, I began with a demo of "BPF superpowers" (aka eBPF). In the video I explained how I arrived at tracing __iwl_dbg() in this way, and how you can follow a similar approach for tracing unfamiliar code. My [BPF Performance Tools] book has plenty of examples.

C++ 52

C++ Education Java AWS 52

SQL Performance

OCTOBER 9, 2019

Consequently, handling our task becomes a no-brainer: DECLARE @s AS VARCHAR ( 20 ) = '123.456.789,00' ; SELECT TRANSLATE ( @s , '.,' , ',' ) ; This code generates the desired output: 123,456,789.00. As an exercise, try solving this task with a pre-SQL Server 2017 compatible solution where you cannot use TRIM and TRANSLATE.

C++ 111

C++ Database Servers Code 111

SQL Performance

JUNE 10, 2020

That is, does SQL Server perform a substitution process whereby it converts the original nested code into one query that goes directly against the base tables? The answer is simple, to shorten the code by having the inner query use the infamous SELECT *. That’s safe and will get handled optimally in terms of index matching.

C++ 109

C++ Database Servers Code 109

Sutter's Mill

FEBRUARY 17, 2020

C++ “move” semantics are simple, and unchanged since C++11. Move: What it is, and how to use it In C++, copying or moving from an object a to an object b sets b to a ’s original value. This post is an attempt to shed light on that situation. That’s it for what advanced users need to know. Yes, but don’t.

C++ 98

C++ Testing Design Strategy 98

Sutter's Mill

JANUARY 25, 2021

We want a way to enable checking for some assertions but not others in the same code, because we may not always be able to afford expensive checks. Example 1(a)’s min <= max is at this other end of the scale: It’s so dirt cheap to check that it’s unlikely we’ll ever have a performance reason to disable it. [2] in production).

C++ 45

C++ Programming Cache Testing 45

SQL Performance

JUNE 10, 2020

That is, does SQL Server perform a substitution process whereby it converts the original nested code into one query that goes directly against the base tables? The answer is simple, to shorten the code by having the inner query use the infamous SELECT *. That’s safe and will get handled optimally in terms of index matching.

C++ 93

C++ Database Servers Code 93

Smashing Magazine

DECEMBER 2, 2021

Advent of Code. If you prefer a puzzle over an article, take a look at Advent of Code. Good ol’ PerfPlanet is back for another season with all things speed and web performance. C# Advent Calendar. It’s time for the fifth annual C# advent calendar that will feature two pieces of content every day. Rock on! ??.

Design 108

Design Development Programming Website 108

The Agile Manager

AUGUST 31, 2021

Each person is responsible for the outcome because team performance is measured on collective output (specifically, stories in production) as opposed to the sum of individual output (tasks completed by individuals). One person who does a substandard job affects the performance of the entire team.

Metrics 52

Metrics Design Engineering C++ 52

ScaleOut Software

AUGUST 20, 2020

This allows application code to introspect on the dynamic behavior of each data source, maintain synthetic metrics which aid the analysis, and create alerts when conditions require. They make use of standard object-oriented concepts and languages (such as C#, Java, and JavaScript). Debugging with a Mock Environment.

Cloud 52

Cloud Development Analytics Azure 52

ScaleOut Software

AUGUST 20, 2020

This allows application code to introspect on the dynamic behavior of each data source, maintain synthetic metrics which aid the analysis, and create alerts when conditions require. They make use of standard object-oriented concepts and languages (such as C#, Java, and JavaScript). Debugging with a Mock Environment.

Cloud 52

Cloud Development Analytics Azure 52

Testlodge

AUGUST 9, 2023

The tester established a baseline by selecting the most critical, common, or obvious path through the code selection. Steps to Performing Basis Path Testing The first step is to create a control flow graph for a specified code section. The second step is to select a baseline path through the code.

Testing 75

Testing Software Software C++ 75

CSS Wizardry

NOVEMBER 3, 2020

A couple of years ago, my first few days on a new web performance project were always slow going. Unless a client hires you to specifically improve the performance of one page, you’ll need a broad view of the whole site or application. All through no fault of the client or the project, but through huge flaws in my own approach.

Speed 292

Speed Ecommerce Metrics Analytics 292

Percona

AUGUST 30, 2023

If a PostgreSQL user wants to change these values, they need to recompile the PostgreSQL from the source code. This can be changed later using the pg_checksums utility, but that will be a painful exercise on a big database. If, at all, there is any crash in between, I am OK to perform the ETL again. Type "help" for help.

Database 101

Database Servers Open Source Tuning 101

SQL Performance

APRIL 14, 2021

It has excellent performance, and there’s quite a lot that you can learn from it. Evaluating earlier solutions, one of the important factors in getting good performance was the ability to employ batch processing. Here are the performance numbers that I got in my test: CPU time = 10032 ms, elapsed time = 10025 ms.

C++ 112

C++ Servers Testing Code 112

The Morning Paper

DECEMBER 8, 2019

At the start of November I was privileged to attend HPTS (the High Performance Transaction Systems) conference in Asilomar. With NVM we have both an opportunity to avoid serialisation overheads, and also an obligation since these overheads would be intolerable compared to the performance of NVM. Early performance results.

Hardware 56

Hardware Programming Media Storage 56

SQL Performance

SEPTEMBER 25, 2020

a AS /* comment here because -- chaos */ int = 5 , @b AS varchar ( 64 ) = 'AS = /* BEGIN @a, int = 7 */ ' 'blat' '' , @c AS int = -- 12. So I wrote some PowerShell code to step through a procedure to see which other tokens were identified. . -- AS BEGIN, @a int = 7 'blat' AS =. /* AS BEGIN, @a int = 7 'blat' AS = -- */. @a

Code 42

Code C++ Database Servers 42

John McCalpin

JANUARY 22, 2018

Introduction: In December 2017, my colleague Damon McDougall (now at AMD) asked for help in porting the fused multiply-add example code from a Colfax report ( [link] ) to the Xeon Phi x200 (Knights Landing) processors here at TACC. Instead, we found puzzle after puzzle. Instead, we found puzzle after puzzle.

Latency 40

Latency Hardware Code Testing 40