SAP BASIS: Oracle Database and Oracle Instantclient Dual Setup for SAP - Why?

Often when looking at ORACLE installations for SAP I have in the past wondered at the difference between the ORACLE database installation and the ORACLE instantclient. What does the ORACLE instantclient add that the database software doesn't include? The answer is, essentially, nothing. This is confusing at first as an SAP installation requires the instantclient in addition to the database installation. This blog explains why...

This may seem, technically, a very simple question, yet due to demarcation of roles between teams you might very well continue in a SAP Basis role for a long time without really knowing the answer. This was my situation until recently - so this blog is to help me to remember and to help you to learn.

So let's start from the start... what scenario led to this question?

Well while working on some migrations I noticed that I'd never questioned why there was an instant client setup being used by SAP. The reason that this is strange, as I have mentioned above, is that the base ORACLE db software installation includes this functionality already, so why install the instant client as well?

Having spoken to several experts I found the answer - the SAP kernel is compatible with more and less advanced versions of ORACLE, however it needs to use the appropriate ORACLE client software (that it was developed for) to access the database.

An example? During one migration we moved a system running on ORACLE 10.2.0.4 to a new server. We only setup a 10204 instantclient on the target as it seemed to make logical sense that this system would no longer need the ORACLE 9i client (which existed on the source) - WRONG! In this case the SAP kernel was a 640 version that required the ORACLE 9i client to communicate with the database!

So the full ORACLE database software installation is required to run the ORACLE database layer, however the ORACLE instantclient is also required to be installed and managed separately, to enable the SAP kernel to work and communicate with the database.

Technical notes==
See SAP kernel file "dboraslib" which utilises the ORACLE instantclient.
On UNIX you can us the "ldd" command (LIST DYNAMIC DEPENDENCIES) to check what libraries this file expects/requires.

SAP notes===
See SAP note 819829 for UNIX, or 998004 for Windows

scategorise? what's coming.. and IKEA and still married... no it's not really very technical yet

I'm not sure if you have to just blast out content using blogger or if you can categorise... anyway I will being aiming for two discrete categories to start off with. SAP and Home Computing. My outline, and this is all just sitting under the recent buzzcut, is to go over cloud computing in relation to SAP, and then to look at home computer backup solutions.

Anyway to give this blog a personal touch I will blog some details of this historic say in the new history of infotechreflect. I have spent this fateful day tiring my stalks going to church, to Toys'R'Us and to IKEA. I've made it through still married and although I'm in some pain I still managed to start a blog, so I seem to have some stamina left now that I'm really entering my 30s.

infotechreflect is born

Glowing wires. Inspiration from various sources. Jeff Jarvis.. Aaron Sorkin.. Jacob Bronowski.. Katie Hafner and Matthew Lyon..

I have found that I desire to blog (is that a verb?) my thoughts on information technology in industry and my experiences with it. Perhaps as a way to structure my own reflections on IT in order to improve my own knowledge. Hopefully also to create links with like-minded people and perhaps foster some discussion.

For those who read this, and for my own catharthis, here is a little background on me. I am a Bachelor of Science, particularly focused on Computing. Following several years of debauchery and many lessons learned from living with some sensible women and not-so-sensible male art students I bumped along to graduate in 2002 from the Manchester Metropolitan University. My dissertation on Effective Web Site Design somehow notched me up a first class degree and yet I proceeded to do only a little web design (professionally and privately) before going on to work as a computer system administrater, a programmer, a DBA and, more recently, an ERP systems consultant.

Currently I work for Hewlett-Packard... still in Manchester, in the UK. I am essentially, for now, a SAP Technology Consultant; although I try and keep abreast of all IT... a hard task!

I want to keep these short and punchy and, as I think I'm failing already (something I'm guilt of on voicemails too..), I'll try and wrap up this intro. My areas of thought currently wander around database design, ERP systems archtecture, ITIL, cloud comuting, virtualisation, OS platforms, home computing and on these topics I will splurge the contents of my grey matter onto this blog.

So - my reflections on information technology - hence, infotechreflect.