Book – The everything store
The everything store
The idea of the everything store was simple: an Internet company that served as the intermediary between customers and manufacturers and sold nearly every type of product, all over the world. It is the story of Amazon.com, one of the most successful companies in the world. And the story of its driven founder Jeff Bezos.
Reading the book I think that there are a few (more...)
Reading list of 2014 so far
In this blog post I’ll share a list of books I read during the first months of 2014. There is more business focus compared to previous years…
The everything store
The everything store is one of the books I liked reading most of my reading list this year. It tells the story of amazon.com so far; The vision and ways of working of the company and it’s founder (more...)
FitNesse add tags to multiple pages at once
We’re using FitNesse as one of our tools for (acceptance) testing. It can be quite laborious in FitNesse to add tags to multiple pages at once. So one my colleagues – Joost van Wollingen – wrote a nifty tool that can mass tag selected pages.
In order to have FitNesse add tags to multiple pages at once, start the Java program. Select the directory from where you (more...)
Enkitec’s Oracle AWR Data Mining Tool
EAdam is a free tool that extracts from an Oracle database a subset of data and metadata with the objective to perform some data mining using a separate staging Oracle database. The data extracted is relevant to Performance Evaluations (PE) and/or to Sizing and Provisioning (SP) projects. Most of the data eAdam extracts is licensed by Oracle under the Diagnostics Pack, and some under the Tuning Pack. Therefore, in (more...)
Enkitec’s Oracle Database 360-degree View
EDB360 is a free tool that executes on an Oracle database and produces a compressed file which includes a large set of small Reports. This set of Reports provides a 360-degree view of an Oracle Database. EDB360 is mostly used for one of the following 3 reasons, listed here in order of frequency of use: 1) Keystone of an Oracle database Health-Check. 2) Kick-off for an Oracle database Performance Evaluation. 3) High-level (more...)
Online product recommendations using Hadoop
One of the leading portals on BigData, Dataconomy, had an interview with a colleague of mine on product recommendations systems. These are systems aimed towards personalizing content and recommending the ‘right’ products, in other words products that inspire customers. The article – The Science Behind the Finding the Perfect Product – is a nice read that covers quite some areas.
At bol.com we use Hadoop for batches, and (more...)
Many tools offer Public APIs, which expose some functionality to other tools. SQLTXPLAIN contains also some Public APIs. They are provided by package SQLTXADMIN.SQLT$E. I would say the most relevant one is XTRACT_SQL_PUT_FILES_IN_DIR. This blog post is about this Public API and how it can be used by other tools to execute a SQLT XTRACT from PL/SQL instead of SQL*Plus.
Imagine a tool that deals with SQL statements, and with the click of a button it invokes (more...)
This post is a hands-on introduction to using on-CPU Flame Graphs for investigating Oracle workloads. This technique is about collecting and analyzing sampled stack trace data to analyze and troubleshoot Oracle processes at the OS level (in particular applied to Linux).Motivations:
The techniques and tools described here can be used for performance investigations
to complement wait-event based information gathered from the Oracle engine, such as information available with ASH and sql monitoring. They (more...)
My carpenter has been putting in a new floor in a room in my house, and I noticed that he makes some of his tools as he goes along.
It’s not that he doesn’t have a hammer and a cordless electric screwdriver. But every once in a while, he needs to move, align or support something in a way that his standard tools do not support. So he immediately builds an ad-hoc tool out of (more...)
This post introduces the latest changes to OraLatencyMap and PyLatencyMap, two custom tools for collecting and displaying Oracle wait event latency details using heatmaps.OraLatencyMap
is a SQL*Plus tool, with a core written in PL/SQL, aimed at studying Oracle random I/O by displaying the latency drill-down of the wait event 'db file sequential read' using heatmaps. The tool can also be used to collect and display event latency histograms for any other Oracle wait (more...)
This post is about a performance analysis technique based on high frequency sampling of wait event history data in Oracle. Two scripts are provided for performing this type of analysis and two example cases are discussed applied to the study random read latency and read workload characterization.
In the context of performance analysis, for example for a study of I/O response time, I want to analyze the flow of all wait events
this article is about a tip for Oracle 11.2 and higher on how to handle DST change when querying directly the AWR repository. In addition a few comments on Perfsheet4, a tool to extract and plot AWR data in Excel.Introduction:
Statspack and more recently AWR reports
At Derbycon 3.0, László Tóth and Ferenc Spala gave a a new presentation “What’s common in Oracle and Samsung? They tried to think differently… ” (Video). The main focus of the presentation was the Samsung encryption and a new framework called sandy but there was also a small (more...)
this is a getting-started article for PyLatencyMap
, a performance tool for real-time investigation and troubleshooting of latency data. Contains examples relevant for the Oracle RDBMS and for DTrace.Getting started
Download the latest version of PyLatencyMap
(also available on GitHub
). At the time of this writing PyLatencyMap (more...)
this post is about PyLatencyMap, a performance-oriented tool I have written for command-line drill down of latency data, integrating various data sources (Oracle, DTrace, trace files) into a basic visualization engine.Motivations:
Understanding a performance problem is often about understanding where time is spent. Many of the systems I (more...)
Lean, agile and Software development reading list of 2013
In this blogpost I’ll share a list of books I read during the first six months of 2013.
Hadoop – The definitive guide
This book proved very useful to get an introduction and solid background in Hadoop. I was reading it (more...)