Thursday, 5 February 2015

Latest SAP HANA Interview Questions and Answers pdf for freshers and experienced pdf free download (Part4)

31. What are the limitations of HANA 1.0?
Quite a few so far - it can only replicate certain data, from certain databases, in certain formats, using the Sybase Replication Server. Batch loading is done using SAP BusinessObjects Data Services 4.0 and is optimised only for SAP BusinessObjects BI 4.0 reporting.

32. What is SAP HANA 1.5, 1.2 or 1.0 SP03?
These are all the same thing, and 1.0 SP03 is touted to be the final name for what should go into RampUp (beta) in Q4 2011. This will allow any SAP NetWeaver BW 7.3 Data Warehouse to be migrated into a HANA appliance. HANA 1.0 SP03 specifically also accelerates BW calculations and planning, which means you get even more performance gains.

33. What's the difference between HANA and IMDB?
 HANA is the name for the current BI appliance (HANA 1.0) and the BW Data Warehouse appliance (HANA 1.0 SP03). Both of these use the SAP IMDB Database Technology (SAP HANA Database) as their underlying RDBMS. Expect SAP to start to differentiate this more clearly as they start to position the technology for use cases other than Analytics.

34. If I can run Net Weaver BW on IMDB/HANA, why can't I run the Business Suite/ERP 6.0?
Simply because it's not mature enough yet to support business critical applications. From a technology perspective, it is already possible to run the Business Suite on IMDB and SAP has trialled moving some large databases into IMDB already.

35. What is HANA great at?
The best thing that HANA brings to the table is the ability to aggregate large data volumes in near real-time - and to have the data updated in near real-time. SAP's demos show hundreds of billions of records of data being aggregated in a matter of seconds. SAP has built a set of Analytics Apps on top of HANA and this are set to be great point use cases to get customers up and running quickly.

36. What is HANA bad at?
There are some current issues around HANA when delivering ad-hoc analytics, especially when using the SAP Business Objects Webi tool. Essentially the problem is that you can ask computationally very difficult questions with Webi, which can cause very long response times with HANA. SAP will need to build optimization for both Webi and HANA to reduce the computational complexity of these questions, but they're not there yet.
 What's more, it's worth noting that HANA 1.0 is not a Data Warehouse and it is more of a Data Mart - that is, suited to point applications where there is a clear use case.

37. What does HANA cost?
SAP hasn't entirely confirmed HANA licensing costs but the hardware is somewhere around $1-200k per TB. Add to this licensing cost which are still being made on a per-customer basis.

38. Why is HANA so fast?
Regular RDBMS technologies put the information on spinning plates of iron (hard disks) from which the information is retrieved. HANA stores information in electronic memory, which is some 50x faster (depending on how you calculate). HANA stores a copy on magnetic disk, in case of power failure or the like. In addition, most SAP systems have the database on one system and a calculation engine on another, and they pass information between them. With HANA, this all happens within the same machine.

39. Does HANA/IMDB replace Oracle?
It's the elephant in the room, but once the Business Suite runs on IMDB, Oracle won't be needed any more by SAP customers who purchase HANA. This doesn't affect anything in the short term because those people buying HANA today will still need an Oracle ERP system.

40. What is this about 10:1 compression with HANA compared to Oracle?
A typical uncompressed Oracle or Microsoft SQL Server database, when put into HANA, will be 10x smaller than before and this is due to the way that HANA stores information in a compressed format. Note that most databases are now compressed and these numbers may not fit your scenario, and to add to this you need 2x the RAM as your database, plus room for growth. HANA sizing is still a dark art.
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