Recently I was implementing the ADF Performance Monitor at a customer site and doing a detailed performance analysis. This customer had severe (and less severe) performance problems but was unable to pinpoint the exact pain points. Frequently, end-users were complaining because they were experiencing first a very good performance (response times less than a second), and then suddenly experiencing a drop in performance for a certain period of time (an hour or so) with response times between five to twenty seconds.
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...)
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...)
Every so often I see on a distribution list a posting that starts like this: “I upgraded my application from database release X to release Y and now many queries are performing poorly, can you tell why?”
As everyone else on a distribution list, my first impulse is to make an educated guess permeated by a prior set of experiences. The intentions are always good, but the process is painful and time consuming. Many of (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...)
Many things, but most important is that it got bigger and better. This EDB360 free tool provided by Enkitec is maturing over time. Its core function has not changed although, which is to present a 360-degree view of a database (10g or higher).
EDB360 is a nice complement to other tools like Exacheck, Raccheck or Oracheck. It has some additional benefits, like taking a snapshot of a system to then be analyzed offline or simply (more...)
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...)
Both eAdam and eDB360 tools are available at the Enkitec web site under the Products tab. You can download a free copy from there; or maybe you were given by an Enkitec consultant a newer version for you to execute. In any case, the question is: “how do I execute these tools?“
- Take the eadam.zip file and unzip it on your server
- Navigate to the top eadam directory which contains (more...)
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...)
Download the latest version of PyLatencyMap (also available on GitHub). At the time of this writing PyLatencyMap (more...)
Motivations: Understanding a performance problem is often about understanding where time is spent. Many of the systems I (more...)
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...)