What is Apache Drill and how to setup your Proof-of-Concept

Apache Drill is a schema-free SQL query engine. Drill supports a variety of NoSQL databases and file systems, including HBase, MongoDB, MapR-DB, HDFS, MapR-FS, Amazon S3, Azure Blob Storage, Google Cloud Storage, Swift, NAS and local files. A single query can join data from multiple datastores. For example, you can join a user profile collection in MongoDB with a directory of event logs in Hadoop. 

Data Analytics

If you do any kind of data (more...)

Thoughts about Oracle Version Change

It’s been about a year since Oracle decided to change their database version schema, from version with a couple of releases (e.g. 12.1 is 12cR1 and 12.2 is 12cR2) to a single annual version (e.g. 18c and 19c). Now, when 18c is stable and 19c is here on the cloud and Exadata and almost here … Continue reading "Thoughts about Oracle Version Change"

Proactive Oracle Support?

You may not be aware but Oracle have been talking about their new ProActive support with user groups. It’s basically trying to show you best practices you should be implementing before stuff goes wrong, and many other useful bits of information.

It covers a lot of areas and is really worth a look, whether you’re using Oracle Database, Linux, MySQL, EBS, JDEdwards or indeed most Oracle products.

The open URL for headline information is: https://www. (more...)

InfluxDB V2.0 – Stack Implementation Proof of Concept

This blogpost will give you detailed instructions and information regarding the InfluxDB stack. Since February 2019 InfluxDB now consists not only the database itself, but also Telegraf, Chronograf and Kapacitor. Later you’ll read about what every part of the stack does.

18-2-2019: Living on the bloody edge, do not run this in production.

What is InfluxDB?

InfluxDB is a time series database made by InfluxData. It is widely used for telemetry and other time related (more...)

Oracle database 19c: documentation released

In january Oracle released the documentation for 19c:

If you are interested in the new features, take a look here:

Very nice is this link: Interactive Architecture Diagram where you can get a very good introduction to oracle database with many pictures like this one:

This new feature i find very interesting:
Root Scripts Automation Support for Oracle Database Installation
Starting with Oracle Database 19c, the database installer, or setup wizard, (more...)

Generate a formatted guid from database – Use Snippets

A very simple quick post today. I'm re-engineering a few Java based Mock Webservices into a SOA Suite/BPEL service.

Some of those generate a soap fault when a message id contains "8888" for instance.
I'd like to generate a GUID based message id, that is formatted with groups of four digits.

Of course there are loads of methods to do that. For instance, the Oracle database has a sys_guid() function for years. It generates a (more...)

Video : Collation and Case-Insensitive Queries in Oracle Database

Today’s video is a run through the Collation functionality introduced in Oracle Database 12c Release 2 (12.2).

If videos aren’t your thing, you can find a lot more information about this subject in my article here.

The cameo in today’s video is Kim Berg Hansen. 🙂



Video : Collation and Case-Insensitive Queries in Oracle Database was first posted on February (more...)

Oracle ASM and Thin Provisioning – How To Reclaim Space

It came to my attention last November that I had crossed the one year anniversary since my last post on flashdba.com. I was so surprised that I immediately decided to write a new post, which took another three months. There are reasons why I’m no longer posting technical blogs about databases and flash, but I’ll cover them in a later post. No, not that late – I hope.

In the meantime, I thought I’d (more...)

csv2db – the little CSV command line loader you always wanted

It was over the last holiday season that I wanted to take some time and play around a bit with data. The outcome was rather different than I initially expected. Rather than having worked with the data, I spent a lot of time trying to get some CSV data loaded into a database. I knew … Continue reading "csv2db – the little CSV command line loader you always wanted"

Oracle’s Autonomous Database (Cloud)

So yesterday I attended the “Autonomous Database GTM Roadmap Sales Workshop” at Oracle’s London office.  This training is for Oracle partners such as Version 1, which is one of Oracle’s strategic partners.

A lot of what is in this blog post is subject to Oracle’s Safe Harbour statement.

Key Takeaways

1 . Maturity

The Autonomous Database is still very new!  It’s like back in 2008 when the first Exadata Machine (V1) (more...)

Oracle OpenWorld Europe : London 2019

Some eleven thousand people descended on Oracle OpenWorld Europe in London last week for two days of business and technical sessions delivered by a mixture of members of Oracle’s product team and end users giving real-world case studies of adoption of Oracle’s Cloud offerings and product roadmaps.


Something that may not surprise anyone is that at OpenWorld, to speak of anything other than Cloud or Autonomous would be somewhat blasphemous.

It’s a shrewd move this (more...)

dbca doesn’t list diskgroups

This is an Exadata machine running GI version and DB version On one of the DB nodes while running dbca, it doesn’t list the diskgroups. it works fine on the other node.

I cheked the dbca trace and found that the kfod command was failing. I tried to run it manually and got the same error:

[oracle@exadb01 ~]$ /u01/app/ op=groups verbose=true
KFOD-00300:  (more...)

Querying the amount of redo in Oracle Database

When a database starts to churn more redo then normal, it is handy to be able to extract the amount of redo over time, to be able to plot this in a graph.  The below allows you to extract this info 🙂

Query for redo generation

Query to obtain the amount of redo generation over time by hour and MB:

set pages 999 lines 400
select to_char(trunc(first_time, 'HH24'), 'DD/MM/YYYY HH24:MI:SS') date_by_hour, sum(round(blocks*block_size/1024/1024)) CHURN_IN_MB
from v$archived_log

Column And Table Redefinition With Minimal Locking

TLDR: Note to future self… (1) Read this before you modify a table on a live PostgreSQL database. If you do it wrong then your app might totally hang. There is a right way to do it which avoids that. (2) Especially remember the lock_timeout step. Many blog posts around the ‘net are missing this and it’s very important.

Yesterday I was talking to some PostgreSQL users (who, BTW, were doing rather large-scale cool stuff (more...)

Oracle Database EM 18 XE Available to Remote Clients

I found lot of posts about Oracle Database 18 XE. It's very interesting for me.  I didn't blog about how to install, because it's very easy for using rpm package and document very helpful.
I was interested in Enterprise Manager Database Express How it looks like?
- Installing. I used CentOS7.
[student@centos-learning ~]$ sudo yum -y localinstall oracle-database*18c*
[student@centos-learning ~]$ sudo rpm -qa |grep oracle
oracle-database-xe-18c-1. (more...)

Exploring Autonomous Databases – Client Credentials

The wallet zip file from ATP or ADW includes the connection information for all the ATP and ADW databases you have created under the cloud account, even though the credential zip file name is "wallet_.zip".

List of Bank Holidays For England in SQL Format

First off, create a table to store the bank holiday values. You may need to adjust this slightly depending on your SQL server technology being used (this was tested on MySQL Server).  [crayon-5bb4e0b3b1755979540269/] Insert the bank holiday values below. This table is currently for 2012 up to 2019 for England and Wales.  [crayon-5bb4e0b3b175d512369946/] For a

MySQL 8: New Features

After installing mysql 8 on my ubuntu i did a lookaround for the new features. Oracle itself stated:

This is really cool, but how to test this?
A first look inside the standard data directory /var/lib/mysql shows:
/var/lib/mysql# ls -l
insgesamt 168012
-rw-r----- 1 mysql mysql       56 Aug 17 20:53 auto.cnf
-rw-r----- 1 mysql mysql      498 Aug 17 20:53 binlog.000001
-rw-r----- 1 mysql mysql      554 Aug 17 21:07 binlog.000002
-rw-r----- 1 (more...)

mysql 8: installation on ubuntu

Today i tried to install mysql 8 on my ubuntu:
First i visited the site https://dev.mysql.com/downloads/repo/apt/ which says:
So i downloaded this file (https://dev.mysql.com/get/mysql-apt-config_0.8.10-1_all.deb) and here we go:

# dpkg -i mysql-apt-config_0.8.10-1_all.deb 

Vormals nicht ausgewähltes Paket mysql-apt-config wird gewählt.

(Lese Datenbank ... 414911 Dateien und Verzeichnisse sind derzeit installiert.)

Vorbereitung zum Entpacken von mysql-apt-config_0.8.10-1_all.deb ...

Entpacken von mysql-apt-config (0.8.10-1) ...


Where to find the oracle-database-ee-18c-1.0-1.x86_64.rpm package?

After writing about the release of Oracle database 18c i wanted to download
to try the rpm-based installation.
But this rpm is not included in
The oracle documentation shows:
 But on OTN and Delivery Cloud only the zipfile without the rpm can be downloaded...

So let's see, when the download pages are updated...