Re: Running general applications on Exedata

I'll chime in Š

Exadata can be fantastic for applications that perform full scans - smart scan and cell offload shine when lots of data is being retrieved, which is why reporting and warehouse types of applications are ideal.

"Not so good for OLTP" seems a bit general to me. For true OLTP applications that do things like single-row queries, any hardware infrastructure that matches what's in an Exadata database machine will and can perform as well, with normal optimization techniques like indexes. There are features in Exadata that are beneficial for OLTP applications in comparison with older technologies (lots of memory, all things considered, Smart Flash Cache, relatively fast CPUs, a fast RAC interconnect, etc) but often the cost of an Exadata alone may not play well against competitive products in true OLTP workloads.

But for mixed workload environments, smart scans and associated software features can help some of the problematic "large IO" queries and the CPU/memory/flash/InfiniBand stuff can make the OLTP applications competitive and at worst, no worse, than other hardware platforms.

• John

From: David Roberts <big.dave.roberts_at_googlemail.com> Reply-To: "big.dave.roberts_at_googlemail.com" <big.dave.roberts_at_googlemail.com>
Date: Saturday, April 28, 2012 12:12 AM To: oracle-l-freelists <oracle-l_at_freelists.org> Subject: Running general applications on Exedata

I'm going to ask quite an open question , so I hope that I don't get slapped down for that, but the chances are, if I haven¹t included the information, then the chances are I don't know, but do ask! Firstly, I'm somewhat lower down the food chain than many on this list, I have no practical knowledge of RAC and setting up my own RAC system in my own virtual environment was something on my to-do list.

I now have the possibility of a sniff at an ExeData machine at Oracles expense to prove our application in that environment.

This was extremely unexpected!

Obviously if I thought that this was even a remote possibility I'd have attended the UKOUG Exa- Special event on Monday like a shot!

So, from almost a standing start;

I know that all the ExeData documentation is locked down and not freely available from docs.oracle.com, so I've purchased the Apress title: Expert Oracle ExeData.

The application isn't particularly large, I'm assuming that if the database instance is only installed on one ExeData node, RAC issues are going to be minimal.

Ultimately it¹s a mixed application with both OLTP and Reporting functions. My
understanding is that Exedata will be brilliant for reporting and not so good for OLTP, and normal tuning tactics for Exedata (like removing indexes) are going to be a non-starter for OLTP performance. And that's my starting position, so anything obvious I've missed? Any obvious sources of ExeData knowledge, any documented approaches to migrating applications to ExeData?

The application is more that 15 years old, largely Oracle Forms based and currently runs in (database) environments from 9i to 11gR2, predominantly on Windows.

Dave

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http://www.freelists.org/webpage/oracle-l Received on Sat Apr 28 2012 - 01:12:50 CDT