Showing posts with label statistics. Show all posts
Showing posts with label statistics. Show all posts

Sunday, 20 March 2016

Myth of HANA

since SAP HANA was avaiable in the year 2011 (GA), I come across a lot of untruth about the new in-memory platform. As consultant I was able to talk to many costumers and other consultants on events like TechED, DSAG, Business partner days etc. Every time I was impressed after this long time that so much dangerous smattering is still out there.
The most answers to the statements are pretty easy to find in the offical notes, guides and other documents (blogs, presentations, articles etc.), but may it is an overload of information.

1) start time
2) cross SID backup
3) col / row store conversion
4) sizing *2
5) statistics
6) data fragmentation
7) persistency layer
8) high memory consumption HANA vs. Linux
9) Backup
10) Backup catalog

Wednesday, 13 January 2016

New Statistics Server Implementation

What is the Statistics Server?

The statistics server assists customers by monitoring their SAP HANA system, collecting historical performance data and warning them of system alerts (such as resource exhaustion). The historical data is stored in the _SYS_STATISTICS schema; for more information on these tables, please view the statistical views reference page on help.sap.com/hana_appliance

What is the NEW Statistics Server?

The new Statistics Server is also known as the embedded Statistics Server or Statistics Service. Prior to SP7 the Statistics Server was a separate server process - like an extra Index Server with monitoring services on top of it. The new Statistics Server is now embedded in the Index Server. The advantage of this is to simplify the SAP HANA architecture and assist us in avoiding out of memory issues of the Statistics Server, as it was defaulted to use only 5% of the total memory.

In SP7 and SP8 the old Statistics Server is still implemented and shipped to customers, but can migrate to the new statistics service if they would like by following SAP note 1917938.

How to Implement the New Statistics Server?

The following screen caps will show how to implement the new Statistics Server. I also make note of what your system looks like before and after you perform this implementation (the steps to perform the migration are listed in SAP note 1917938 as well).