Enkitec’s Oracle AWR Data Mining Tool

eAdamEAdam 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...)

Einfügen von Zeilen aus Excel im SQL Developer

Dass der SQL Developer ein großartiges Tool ist, dem ich womöglich verfallen wäre, wenn ich meine Seele nicht an sqlplus verkauft hätte, habe ich vielleicht gelegentlich schon mal erwähnt. Ein in entsprechender Situation sehr nützliches Detail zeigt Jeff Smith in einem aktuellen Blog-Eintrag: die Möglichkeit, Daten aus Excel per Copy&Paste im SQL Developer in eine Tabelle einzufügen. Das zumindest kann ich mit sqlplus nicht durchführen...

ADF Performance Monitor: Measuring Slow Network Time

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.

In (more...)

Online product recommendations using Hadoop

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.

Stack of Hadoop nodesAt bol.com we use Hadoop for batches, and (more...)

SQLTXPLAIN PL/SQL Public APIs to execute XTRACT from 3rd party tools

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...)

PDF über PL/SQL erzeugen

Zur Unterstützung meines unterstützungsbedürftigen Gedächtnisses: Morton Braten zeigt einige Möglichkeiten zur Erzeugung von PDF-Reports über PL/SQL.

Flame Graphs zur Analyse der Entwicklung des Oracle Optimizer

Luca Canali kombiniert in seinem Artikel Oracle Optimizer Investigated with Flame Graphs die von Brendan Gregg entwickelte Visualisierungstechnik der Flame Graphs mit den von Tanel Poder zusammengetragenen Informationen zur stack trace Analyse im Rahmen des Troubleshootings in Oracle Datenbanken. Dabei zeigt er anhand eines überschaubaren Beispiels die unterschiedlichen Graphen, die sich für eine Query ergeben, die zunächst mit dem rule based optimizer (RBO), dann mit dem cost based optimizer (CBO) der Version 11 und schließlich (more...)

Flame Graphs for Oracle

Topic: 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...)

Recent Updates of OraLatencyMap and PyLatencyMap

Topic: 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...)

Wait Event History Sampling, an Experiment in Oracle Performance Analysis

Topic: 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.

Context: 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 for (more...)

Daylight Saving Time Change and AWR Data Mining

Topic: 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, (more...)

Decrypt Oracle and database link passwords

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...)

Getting Started with PyLatencyMap: Latency Heat Maps for Oracle and DTrace

Topic: 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...)

PyLatencyMap, a Performance Tool for Latency Data Visualization

Topic: 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...)

Creating hidden paths in Powerpoint

When you are, like me, creating presentations you might want to have the possibility to hide certain slides and only show them when time permits. You can of course just skip over the slides during your presentation, but that is not a good practice IMHO. It is better to add (more...)

Lean, agile and Software development reading list of 2013

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

Hadoop the definitive guideThis book proved very useful to get an introduction and solid background in Hadoop. I was reading it (more...)


Last couple of weeks I have been working on an update of the Favorites plugin for PL/SQL Developer. After extensive testing by Erik van Roon, Henk Jan van Wijk and Marcel Hoefs I decided to release it. Hope you like it.

Menu Items


Add Current

Adds the current file (more...)

New release of the APEX Developer Addon

After the APEX Developer Addon broke in Chrome 27, I had to change the underlying architecture and do a rewrite of the Addon basis.

Some nice guys helped me Beta-Test that over the last week. Now it should be good to go.

Now here is the tricky part: if you already use the Developer Addon, then you have to uninstall that and get the new one from the Project Page.

That’s it. Enjoy !

P. (more...)