August 2016

Oracle Database Cloud (DBaaS) Performance Consistency - Part 2

This is the second part of this installment, comparing the performance consistency of the DBaaS cloud offering with a dedicated physical host. This time instead of burning CPU using a trivial PL/SQL loop (see part 1) the test harness executes a SQL statement that performs logical I/O only, so no physical I/O involved.

In order to achieve that a variation of Jonathan Lewis' good old "kill_cpu" script got executed. In principle each thread performed the following:

define tabname = &1

define thread_id = &1;

Basicfile LOBs 1

I got a call to a look at a performance problem involving LOBs a little while ago. The problem was with an overnight batch that had about 40 sessions inserting small LOBs (12KB to 22KB) concurrently, for a total of anything between 100,000 and 1,000,000 LOBs per night. You can appreciate that this would eventually become a very large LOB segment – so before the batch started all LOBs older than one month were deleted.

The LOB column had the following (camouflaged) declaration:

How to make Apple Airport wifi routers do remote logging.

This is a blog not related to Oracle products in any way.

Remote logging.
This post is specific to apple Airport Extreme and Express wifi routers. However, in general: if you have multiple (unix/linux) servers, it makes sense to centralise the (sys)logging of these servers, in order to get a better overview on what is happening on these servers. I would want to go as far as saying that if you don’t you are simply not doing it right.

The central logging can be another syslog deamon receiving the logging, but there are many more products who are able to receive logging, like splunk, graylog, logstash and so on. This blogpost is about my home wifi routers, I use the simple and limited Synology “Log Center” daemon.

Data Redaction and Data Pump in #Oracle 12c

What happens upon Data Pump Export if tables are being exported that have a Data Redaction Policy? I got that question several times in class, which is why I put the answer here , so I can refer to it subsequently.  Might also be of interest to the Oracle Community:-)

Oracle 12c: Indexing JSON in the Database Part II (Find A Little Wood)

In Part I, we looked at how you can now store JSON documents within the Oracle 12c Database. For efficient accesses to JSON documents stored in the Oracle database, we can either create a function-based index based on the JSON_VALUE function or on JSON .dot notation. These indexes are useful for indexing specific JSON attributes, […]

The Book.

I’ve just added a picture to the right side of this site. It is for a book about SQL and PL/SQL. If you look at the image of the front cover, at the bottom is a list of authors and, near the end, is my name. It’s all finished and at the printers, but it is not out yet – It should be published in the next few weeks.

The British part of me wants to mumble and say “oh, yes, hmmm, I did contribute to a book… but I think you should concentrate on the chapters by the other chaps, they are proper experts, very clever gentleman and lady… I was just involved in a couple of lesser chapters…”

The part of me that spent weeks and months of late nights and long weekends writing it wants to scream “Look! LOOK! I damn well got it done! And it was way more painful than any of my author friends told me it would be as, despite their best efforts, I did not get How Hard Writing A Book Is!
I BLED FOR THAT BOOK!”

DBMS_STATS - Gather statistics on tables with many columns - 12c update

This is just a short 12c update on my post about gathering statistics on tables with many columns from some time ago.I'm currently investigating the "Incremental Statistics" feature in 12.1.0.2 for a client, which probably will be worth one or more other posts, but since we're still in the process of evaluating and installing various patches it's too early to write about that.As part of the investigation I've noticed a significant change in behaviour in 12.1.0.2 compared to previous versions when it comes to gathering statistics on tables with many columns, hence this post here.The key message of the original post was that DBMS_STATS needs potentially several passes when gathering statistics on tables with many columns, which meant a significant increase in overall work and resource consumption, exaggerated by the fact that tables with that many colu

Introducing a VCE White Paper. Consolidating SAP, SQL Server and Oracle Production/Test/Dev/OLTP and OLAP Into a Single XtremIO Array with VCE Converged Infrastructure.

This is just a short blog post to direct readers to a fantastic mixed-workload and heterogeneous database consolidation Proof of Concept. This VCE paper should not be missed. I assert that the VCE converged infrastructure platforms–most notably the Vblock 540–are the best off-the-shelf solution for provisioning XtremIO storage array all-flash storage to large numbers of hosts each processing vastly differing workloads (production,test/dev,OLTP,OLAP).

This paper is full of useful information. It explains the XtremIO 24:1 data reduction realized in the test. It also shows a great deal of configuration tips such as controlling I/O on Linux hosts with CGROUPS and on VMware virtual hosts via VMware Storage I/O Control.

The following is an overview of the testing landscape proven in the paper:

A total unattended install of linux and the Oracle database.

This is a blogpost about how I setup my test virtual machines. The seasoned sysadmin and DBA will notice that the techniques used here are perfectly usable for real production environments. The most important thing is there is no need to download or stage any software for installing the virtual machine, everything is downloaded when needed during installation. Obviously this works best when you have got reasonable bandwidth available for connecting to the internet.

The main infrastructure software components of this setup are:
Virtualbox as the virtualisation software.
Ansible as the configuration and management engine.
Vagrant as the virtualisation manager.

Oaktable World 2016

oaktable world 2016
Event date: 
Mon, 2016-09-19 - Tue, 2016-09-20

Anyone who’s anyone knows to search out OakTable World at major events in the US and Europe, and Oracle Open World 2016 is no different!

OakTable World 2016, (#otw16) will be held at the Children’s Creativity Museum again this year during the week of Oracle Open World.  The Oak Table members will be discussing their latest technical obsessions and research on Monday and Tuesday, (September 19th-20th).  The truth is, folks-  The Oak Table experts are an AWESOME group, (if I don’t say so myself! :)) as we could have easily done another day of incredible sessions, but alas, two days is all we have available for this year’s event.