HANA backtrace 45/2011

Ok, it’s been more than the planned week since my last post in this series (HANA backtrace 44/2011) but these are very busy times lately for a primary support guy like I am.

I write this post from our US Headquarter offices in Newtown Square near Philadelphia and that’s because I’ve been asked to deliver several internal HANA training workshops for our AGS colleagues over here. Thus, I booked the flight, packed my bag and flew over here.
And there we are – right in the middle of a quite packed training week, covering topics like performance analysis, modelling, data services and backup/recovery (and lots more).
And just as we’re in full flight, we see HANA SPS 03 being released to customers.

With this, many new features, usage types and bug fixes have been made available to HANA users.
Make sure not to miss out on the updated SAP HANA documentation.

For the HANA database, this is revision 20 and the changes that have been made in this revision are documented in SAP note #1648901 SAP HANA database Revision 20.

The actual SPS 03 release notes can be found as an attachment to SAP note #1642937 SAP HANA Appliance Software SPS 03 Release Note.

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With SPS 03 a new software installation tool (Software Update Manager, SUM)  had been released for HANA systems.
See SAP note #1545815 SAP Release Note for SUM for SAP HANA 1.0 to get the details.
The nice thing about this is, you can easily manage the upgrades of HANA related software parts all at once.

Also very important to know is that with SPS 3 now log backups are supported with the HANA database.
Note #1645183 Changing log mode for SAP HANA DB after SPS2 to SPS3 upgrade talks about the changes in log mode that have to be implemented for this to get activated.

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With SPS 03 a new way to access data from a HANA system had been released to customers: the web-based SAP HANA Information Composer. Find details in the following two notes

#1627904 SAP HANA Information Composer: Central Note
#1633168 SAP HANA Information Composer: SP3 Release Note

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Just a small code fix for a data type change for function module TREX_EXT_SHOW_INDEX is delivered by sap note
#1652229 SAP HANA: error code -10404 with TREX_EXT_SHOW_INDEX

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As far as I know, the pricing in HANA is based on the amount of data used with HANA, so the importance of a proper sizing is self-explanatory. SAP Note
#1637145 SAP BW on HANA: Sizing SAP In-Memory Database
contains the information about how to size a HANA system if you want to migrate your existing SAP BW system to it.

Which reminds me: BW on HANA has also been made available by the release of HANA SPS 03 and SAP BW SP5.

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Also related to the migration of ABAP systems to run on HANA is note
#1634681 DB Migration: Report for finding large Row Store Tables
which basically makes sure that you don’t overlook very large tables that should be put to the row store.
Why can this be an issue?
That’s because unlike column store tables, row store tables are always fully loaded into memory on HANA instance startup. So if too much data is put into such tables, it might be that the instance won’t come up anymore, since the automatic loading of these tables fails.

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As with all NetWeaver main databases, which is a use case for HANA as well (e.g. BW on HANA) there is the usage of a database sequence called DDLOG_SEQ. Unfortunately, older HANA revisions didn’t support persisted sequences, so after a restart of the HANA instance, the instance would actually be reset to its initial value.
To prevent this, see SAP note #1648526 Incorrect values for DDLOG sequence.

Talking about HANA usage with NetWeaver systems, the database interface library (DBSL) is a core piece of technology – so make sure to have SAP note #1600066 – verfügbare Patches der DBSL für NewDB on your radar to keep track of the latest fixes to it.

And, while you’re already at it, just also check SAP note #1597627 – HANA connection about the secondary database connection with HANA.

In case you should check your SM21 system log from time to time and find error messages that indicate ‘database system is not supported’ since you’re running on HANA, then SAP note #1650209 SM21 Meldung: “Datenbank System wird nicht unterstützt” is for you.

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I was quite happy to learn that there are also helper tools for HANA created for mere support folks like me when I found SAP note #1647717 Für den SAP-Support: Prüfprogramm für Tabellen.
This note contains a little check program that looks out for tables stored in HANAs column store that might require a MERGE of the delta indexes (in case the automatic MERGE had been turned off).

Nicely also SAP note #1652078 SAP HANA database: Hardware check is also kinda support related.
Since HANA revision 18, a little python script is delivered with HANA and executed during installation time.
It basically checks and reports whether your hardware is actually supported for HANA and it looks like my test instance definitively is not… 🙁

logon as root...
vml3012:/usr/sap/HAN/SYS/exe/hdb/python_support # python HanaHwCheck.py
performing Hardware check......
could not get Hardware Information: 'CPU Flags'
assuming largest storage device  /sapmnt/vml3012/a as data device....
assuming 2nd largest storage device  /dev/shm as log device....
System Manufacturer            VMware, Inc.              not supported
System Product Name            VMware Virtual Platform   not supported
could not get Hardware Information: 'CPU Model'
Hardware check failed!!

As a final support related sap note, there is #1641210  SAP HANA datebase: Checking for suspected problems.
So, in case there is any kind of issue, it’s sure a good idea to go through the steps mentioned in this one to avoid the common “traps”.

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For the SLT users, the following SAP notes are surely a must read/implement:

#1605140 SAP HANA 1.0: Central Note – SAP LT Replication Server
#1647648 HANA LTR – corrections for DMIS 2010 SP4 111031 (stop repl)
#1625755 SAP LT Replicator – individual table settings
#1649910 Applying SLT (DMIS_2010 SP05)with SAP HANA SPS03
#1650191 Syntax change in NEW-DB 111108

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In case you’re running HANA on IBM storage you should give SAP note #1650046 GPFS maintenance after SAP HANA node has failed a read to learn about the required checks to be performed when a cluster node failover happened.

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Other releases

As I barely had time to go through the notes while preparing my training sessions, I didn’t make it to the blogs on HANA this week. However, I’ve seen that there had been several HANA related posting, especially in connection to the recent SAP TechED, so give yourself a treat and check “SAP Blogs on In-Memory Business Data Management”  to catch up with them

So, that’s it for this week. I expect more to come for HANA, so see you next week.

HANA backtrace 44/2011

This week I’m starting a new blog post series aimed at the readers that are technically interested in SAP HANA but don’t want to spend hours each week checking every new post, article, forum discussion or sap note about this hot topic.

These regular posts will be little collections of what I found interesting, notable or important in the area of HANA.
Since I’m rather the technology guy and severely biased towards the database-backend-part of it, it shouldn’t surprise anybody that this is not going to be a comprehensive overview that covers all HANA related topics.
Instead, it’ll merely be what I read on the topic – so I hope you like this 🙂

If one or the other now thinks “hmm… this concept is somewhat familiar…” then you’re absolutely right. I really like Pythians “Log Buffer) a lot and HANA is just missing there.

So let’s start and look what the last week (CW 44, 29.10. – 5.11.2011) had for the HANA community:

Several SAP notes had been published

The most important to start with: Revision 18 of the SAP HANA database (and of the related client software of course) had been released and it fixes a lot of issues. On top of that, it also brings several enhancements, especially in the area of the error handling with delta index merging… at least this is mentioned twice in SAP note #1646454 SAP HANA appliance: Revision 18 of SAP HANA database

[...]
o Improved error handling for delta merge
o Improved delta merge error handling
[...]

Maybe they double-enhanced it … 🙂

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If you’re using the segment builder from the SAP CRM solution and want to access HANA then SAP note #1577019 SAP HANA Database: Abap module for Segment Builder is for you.

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SAP BW on HANA is about to be published soon, so sizing is a topic that will become important. Details on this can be found in note #1637145 SAP BW on HANA: Sizing SAP In-Memory Database.

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HANA instances can, of course, be monitored via the DBACockpit like any other supported DBMS. As a security enhancement, there is now a special user (DBACOCKPIT<SID>) setup available that allows the DBACockpit usage with minimal permissions for the monitoring user account.
SAP note #1640741 Different database user for DBA Cockpit for SAP HANA has all the details.

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If you want to install all already published SAP BASIS corrections in one go, make sure to check SAP note #1644214 Comp. SAP Note Basis porting to SAP HANA DB, NW 7.30 SP06.
It’s a composite note that contains all HANA related corrections for SAP BASIS 7.30.

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In case you’re moving your SAP BW system to HANA you won’t need to export the aggregate fact tables since these aren’t necessary anymore with HANA. The correction from SAP note #1644396 SMIGR: Kein Datenexport der Aggregate-Tabellen modifies the famous SMIGR_CREATE_DDL report accordingly.

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For the rare cases where you want to create a database index just for a HANA instance, you need to set this up in the ABAP dictionary. SAP note
#1644788 Datenbank-spez. Index: SAP HANA DB ist nicht in Auswahlliste now allows to actually select HDB in the GUI by adding the value ‘HDB’ to the list of values of domain DDIXDBSEL.

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SQL Hints will still be with us with HANA and SAP note #1645317 SQL Hint wird nicht im Datenbank Trace angezeigt makes sure that we’ll even see them in the SQL trace (ST05).

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By using secondary database connections it’s possible to run your reports against several HANA instances. Unfortunately, there had been a bug with the initialization of the connection information – but no more: SAP note #1646010 SAP HANA: different DB connections are not handled correctly fixes this!

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Although HANA database provides many different client technologies SAP provides support just for a defined set of them.
Make sure to check SAP note #1577128 Supported clients for SAP HANA 1.0 to figure out, which combination of HANA database and clients are actually supported.

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Finally, two SAP notes for the trigger based data replication solution for HANA (LTR for Landscape TRansformation, not for L-language TRigger, or License To Rage … ) provide fixes for bugs:
#1647648 HANA LTR – corrections for DMIS 2010 SP4 111031 (stop repl) #1648783 HANA LTR – corr for DMIS 2010 SP4 11/11/03 (pool 16+keys)

Other releases

In Siri + HANA Sina Moatamed discusses future use cases of HANA and interface technology like Apples Siri.

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SAP BW on HANA will surely be the next big thing and a lot of people have a lot of different guessing about this. In How BW-on-HANA Combines With Native HANA Thomas Zurek explains how it’s actually going to work. Definitively worth the time to read!

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In Why SAP HANA 1.0 SP03 – Project Orange – will be a runaway success John Appleby explains why BW on HANA really will turn out great.

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Test driving HANA is what many customers and partners ask for and Jeff Word lays out the current options in his blog SAP HANA Test Drive in Madrid.

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If you’re now really interested in becoming involved with HANA you may check Paul Desmonds Experienced HANA? How to Educate Yourself about SAP HANA blog post.

Et fini!

That’s it for this week and for the first issue of this little backtrace of my HANA readings. Hope you liked it.

A nice weekend for everyone!