TOI

Uwe Hesse's picture

Understanding Partitioning in #Exasol

Exasol introduced Partitioning in version 6.1. This feature helps to improve the performance of statements accessing large tables. As an example, let’s take these two tables:

 

Uwe Hesse's picture

Accelerate your #BI Performance with #Exasol

Your BI users complain about slow performance of their analytical queries? Is this your Status Quo?

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Uwe Hesse's picture

Account locking in an Active Data Guard environment

During the Data Guard round table of the excellent UKOUG Tech18 conference I got aware of this topic that I’d like to share with the Oracle community:

What is the locking behavior for user accounts in an environment where users may connect to the primary as well as to the standby database?

Uwe Hesse's picture

#DOAG2018 Impressions

As every year in November, the database circus moved to Nuremberg on behalf of the annual DOAG conference. As you may know, this conference has very high standards in terms of turnout and top-notch speakers and it reached them once again: It was a great event!

It started with the welcome keynote where Stefan Kinnen told us that the conference attracted over 2000 attendees and more than 400 speakers from all over the world. That should make it the largest database conference in Europe, I suppose!

Uwe Hesse's picture

Installing an #Exasol 6.1 Cluster on VirtualBox

After having installed the latest VirtualBox version, an ISO file with the latest Exasol version has to be downloaded. The machine hosting VirtualBox should have at least 16 GB RAM and 80 GB free disk space in order to run a 2+1 Cluster with 3 data nodes and one license server. I’m doing it on my Windows 10 notebook.

Uwe Hesse's picture

Understanding Distribution in #Exasol

Exasol doesn’t need much administration but getting distribution right matters

Exasol uses a clustered shared-nothing architecture with many sophisticated internal mechanisms to deliver outstanding performance without requiring much administration. Getting the distribution of rows between cluster nodes right is one of the few critical tasks left, though. To explain this, let’s say we have two tables t1 and t2:

Uwe Hesse's picture

Using the Query Cache for good performance in #Exasol

The result of a query can be cached in Exasol to the effect that repeated identical queries complete in no time. This feature has been introduced in version 5 and is enabled by default.

SQL_EXA> select session_value,system_value  from exa_parameters where parameter_name='QUERY_CACHE';
EXA: select session_value,system_value  from exa_parameters where parameter...

SESSION_VALUE        SYSTEM_VALUE
-------------------- --------------------
ON                   ON

1 row in resultset.

The Query Cache can be (de-)activated on the session level as well as on the system level.

Uwe Hesse's picture

#Exasol Database whoami

This little script displays some useful meta-information:

Uwe Hesse's picture

Automatic Table Reorganization in #Exasol

Exasol Logohttps://uhesse.files.wordpress.com/2018/05/exasol_logo.png?w=150 150w" sizes="(max-width: 161px) 100vw, 161px

Uwe Hesse's picture

Scripts for Batch-Processing using the Data Dictionary in #Exasol

https://uhesse.files.wordpress.com/2015/10/helps.png?w=600&h=558 600w, https://uhesse.files.wordpress.com/2015/10/

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