CQRS through Twitter – more fun than meaning

As part of my 50 Shades of Data presentation, I talk about CQRS – Command Query Responsibility Segregation. The idea that you can have one or more read only data stores with data replicated from the master store where all data manipulation (commands) take place. In a different presentation, I introduce Apache Kafka and explain its concepts. In this article, these two topics come together, in a light hearted fashion.

My starting point is the (more...)

Querying connected data in Graph databases with Neo4j

TL;DR;

· Graph databases are ideal for query use cases with data with complex relationships and layers of connections

· Its query language is fast, efficient and allows for retrieval of information at deeper levels of abstraction in the data

· Neo4j is currently the most popular Graph database, and its declarative query language is Cypher

· Concepts in Cypher are “nodes”, “relationships”, and “properties” for storing the data

· Keep queries small and simple (more...)

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...)

Pass Summit 2018 Keynote 11/7

So I made it to PASS Summit 2018.  After a flight from an airport with one gate-  yes, you heard me right, one gate.  No Wi-Fi, no connectivity and four employees at the airport.  It was a new level of disconnect.

After a number of parties last night, I’m at the bloggers table for the first keynote this morning.  The first keynote started with an energized talk from PASS president and (more...)

Oracle APEX: the low-code and low-cost application middle tier

Oracle APEX is a low code application development framework. It can be used free of charge – either as part of an existing Oracle Database license or running in the free Oracle Database 18c XE product. An Oracle APEX application should be considered a three-tier application – consisting of a client tier (the browser), the middle tier (the APEX application engine) and the data tier (back end databases and REST APIs on top of various (more...)

Querying and Publishing Kafka Events from Oracle Database SQL and PL/SQL

IMG_6351One of the session at CodeOne 2018 discussed an upcoming feature for Oracle Database – supported in Release 12.2 and up – that would allow developers to consume Kafka events directly from SQL and PL/SQL and – at a late stage – also publish events from within the database straight to Kafka Topics. This article briefly walks through the feature as outlined in the session by Melli Annamalai, Senior Principal Product Manager at Oracle.

(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 18.4.0.0.0. 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-preinstall-18c-1.0-1.el7.x86_64
oracle-database-xe-18c-1. (more...)

Rapid generation of Oracle DDL scripts for Tables, PL/SQL APIs, Sample Data

imageYesterday, at the Oracle ACE Directors Product Briefing, I received a gift. It is called QuickSQL. And it is a free online service that generates SQL DDL and DML scripts. The gift in this case was the knowledge about this service – I was not aware of it.

image

Go to http://quicksql.oracle.com. Try it out. If you have a need for a quick set of database tables for a demo or a prototype – (more...)

How to deploy InfluxDB in Azure using a VM service with dedicated storage

 

InfluxDB isn’t natively supported on Azure. This blog post will teach you how to deploy InfluxDB (or any other database) in a VM  with a managed disk on the Azure platform. This will enable you to use this fast time-series database for your project. If the standard range of supported databases (MySQL, CosmosDB, …) on Azure doesn’t suffice. This blog post is for you.

Prerequisite:

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

Recreate Database Using Only Datafile and Logfile

Let’s have look on the steps are used by Oracle DBA  for “Recreate Database Using Only Datafile and Logfile”.
Backup of the control file in trace

SQL> ALTER DATABASE BACKUP CONTROLFILE TO TRACE;

create password file and service

D:\> orapwd file=D:\oracle\product\10.2.0\db_1\database\PWDdba71.ora password=sys entries=10

D:\> oradim -new -sid dba71 -intpwd sys -maxusers 10 -startmode auto -pfile D:\oracle\product\10.2.0\admin\dba71\pfile\init.ora

set the environment and start the database in nomount

D:\>set oracle_home=D:\oracle\product\10.2.0\db_1
 (more...)

Create Oracle Database 18c on Windows – Advanced Configuration for the pros

If you are setting up a production system or similar, you will need to go through the advanced configuration. The best option is to choose "Set Up Software Only" in Oracle Universal Installer (OUI) to complete the Oracle software installation, then use Database Configuration Assistant (DBCA) to create a new database. OUI and DBCA have the advanced configuration. The OUI advanced configuration is not "advanced" enough, DBCA lets you customize the database configuration options - (more...)

Create Oracle Database 18c in 3 clicks!

After the Oracle Database 18c software install, the database creation is only 3 clicks using the Database Configuration Assistant! The Oracle defaults are OK!

Oracle18c Database on your Windows laptop in 6 clicks!

Oracle Database 18c (18.3) is available for download for windows platform since August 22, 2018. If you are new to Oracle or if you are a developer and need a database to play with, you can install an Oracle database quickly on your laptop with a few clicks.

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) ...

(more...)

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
oracle-database-ee-18c-1.0-1.x86_64.rpm
to try the rpm-based installation.
But this rpm is not included in
LINUX.X64_180000_db_home.zip
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...

Oracle 18c database is released for Linux (on premise)

After my posting nearly a week ago about the published 18c documentation on monday the binaries for Oracle 18c database were released:


and

 Here the link to the download page: oracle.com

In one of the next postings i will try a rpm installation...

Session using a database link hangs on “SQL*Net more data from dblink”

I have a client who recently move a database server from on-premise to a Cloud provider.  A database on this database server had a database link to their E-business database in the Oracle Cloud.  Since the move, any sessions in the database that use the database link to the E-business database would hang if the query was to return large dataset.

Below is selecting from dual over the database link that worked:

SQL>  (more...)