SAP HANA Basic Interview Question
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SAP HANA INTERVIEW QUESTIONS
1. State the different types of replication techniques?
The three types are as below:
ETL based replication using BODS
Trigger based replication using SLT
Extractor based data acquisition using DXC
2. What is SLT?
The full form of SLT is SAP Landscape Transformation which is nothing but a trigger based replication. It
is the replication technology to pass the data from the source system to the target system. Here the source
can be either SAP or non-SAP whereas the Target system is SAP HANA system which contains HANA
database.
3. Can we load and replicate data from one source system to multiple target database
schemas of HANA system?
Yes. It can be loaded and replicated for up to 4.
4. Can the type of data load and replication be specified?
It can be either in real time, or scheduled by time or by interval.
5. Define Configuration in SLT?
The information required to create the connection between the source system, SLT system, and the SAP
HANA system is specified within the SLT system as a Configuration. A new configuration in Configuration
& Monitoring Dashboard (transaction LTR) can hence be defined.
6. Is there any need of pre-requisite before creating the configuration and replication?
DMIS add-on is installed in SLT replication server for SAP source systems. The role
IUUC_REPL_REMOTE is assigned to the user for RFC connection but not DDIC. DMIS add-on is not
required and grants a database user sufficient authorization for data replication for a non-SAP source
system.
7. Define what is Configuration and Monitoring Dashboard?
They are applications that run on SLT replication server to specify configuration information (such as
source system, target system, and relevant connections) so that data can be replicated. The replication
status (transaction LTR) can also be monitored.
Status Yellow occurs due to triggers which are not yet created successfully.
Status Red occurs if master job is aborted (manually in transaction SM37).
8. What is advanced replication settings?
Advanced Replication settings is a transaction that runs on SLT replication server to specify advanced
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replication settings like modifying target table structures, specifying performance optimization settings
that defines transformation rules.
9 Define Latency?
Latency is the length of time to replicate data (a table entry) from the source system to the target system.
10. What is logging table?
A logging table in the source system that can record any changes to a table that is being replicated. This
thereby ensures that SLT replication server can replicate these changes to the target system.
11. What are Transformation rules?
Transformation rule is a rule specified in the Advanced Replication settings transaction for source tables
such a way that the data is transformed during the replication process. For example one can specify rule to
Convert fields, Fill empty fields and Skip records
12. When a new configuration is set up what happens?
The database connection is automatically created along with GUID and Mass transfer id (MT_ID).
Configurations with the same schema name can be created which is ensured by schema GUID.
The naming of SLT jobs and the system can uniquely identify a schema where the Mass transfer ID is
used.
13. What are the factors that influence the change/increase the number of jobs?
The factors that influence the change or increase in the number of jobs are number of configurations
managed by the SLT replication server, number of tables to be loaded/ replicated for each configuration,
expected speed of initial load, expected replication latency time. As a thumb rule, one BDG job should be
used for each 10 tables in replication to achieve acceptable latency times.
14. When is the number of Data Transfer jobs changed?
The number of data Transfer jobs changes when the speed of the initial load/replication latency time is
not satisfactory, if SLT replication server has more resources than that is initially available. The number of
initial load jobs may be reduced after the completion of the initial load
15. Mention the jobs involved in replication process?
The main jobs involved in the replication process are stated as below:
Master Job (IUUC_MONITOR_<MT_ID>)
Master Controlling Job (IUUC_REPLIC_CNTR_<MT_ID>)
Data Load Job (DTL_MT_DATA_LOAD_<MT_ID>_<2digits>)
Migration Object Definition Job (IUUC_DEF_MIG_OBJ_<2digits>)
Access Plan Calculation Job (ACC_PLAN_CALC_<MT_ID>_<2digits>)
16. State the relation between the number of data transfer jobs in the configuration
settings and the available BGD work processes?
In SLT replication server each job occupies 1 BGD work processes and for each configuration, the
parameter Data Transfer Jobs would restrict the maximum number of data load job for each mass
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transfer ID (MT_ID).
At least 4 background jobs are required for a mass transfer ID requires to be available. They are One
master job , One master controller job ,At least one data load job ,One additional job either for
migration/access plan calculation/to change configuration settings in “Configuration and Monitoring
Dashboard”.
17. If the parameter set for “data transfer jobs” to 04 in a configuration “SCHEMA1”, a
mass transfer ID 001 is assigned. In such a case what jobs should be in the system?
The jobs should be 1 Master job (IUUC_MONITOR_SCHEMA1), 1 Master Controller job
(IUUC_REPL_CNTR_001_0001) and at most 4 parallel jobs for MT_ID 001
(DTL_MT_DATA_LOAD_001_ 01/~02/~03/~04)
If at the same time lots of tables are selected for load / replication, there could be a chance that there are
not enough background jobs available to start the load procedure for all tables immediately. In such a case
the number of initial load jobs can be increased, or else tables will be handled sequentially.
For tables with large volume of data the transaction “Advanced Replication Settings
(IUUC_REPL_CONT)” to further optimize the load and replication procedure for dedicated tables can be
used.
18. After the SLT replication is over what happens?
After the replication is over, the SLT replication server creates 1 user, 4 roles, 2 stored procedures and 8
tables as mentioned below:
1 User
1 Privilege
4 Roles
<REPLICATION SCHEMA>_DATA_PROV
<REPLICATION_SCHEMA>_POWER_USER
<REPLICATION_SCHEMA>_USER_ADMIN
<REPLICATION_SCHEMA>_SELECT
2 Stored procedures
RS_GRANT_ACCESS, RS_REVOKE_ACCESS
8 Tables
DD02L, DD02T, RS_LOG_FILES, RS_MESSAGES, RS_ORDER, RS_ORDER_EXT,
RS_SCHEMA_MAP, RS_STATUS
19. State the different replication scenarios?
The different replication scenarios are Load, Replicate, Stop, Suspend and Resume.
Before any application table is selected, the initial load of the tables DD02L, DD02T & DD08L must be
completed as they contain the metadata information.
Load: This starts an initial load of replication data from the source system. The complete procedure is a
one-time event. Once completed, further changes to the source system database will not be replicated.
Also for the initial load procedure, neither database triggers nor logging tables are created in the source
system. The default settings use reading type 3 (DB_SETGET) with up to 3 background jobs in parallel to
load tables in parallel or subsequently into the HANA system.
Replicate: This combines an initial load procedure and the subsequent replication procedure (real time or
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scheduled).
Before the start of initial load procedure, trigger of database and related logging table are created for each
table in the source system as well as in SLT replication server.
Stop Replication: This stops any current load or replication process of a table.
The stop function removes the database trigger and related logging tables completely. This function is
used only if you want to continue a selected table otherwise it must be initially loaded again to ensure data
consistency.
Suspend: This pauses a table from a running replication. Also the database trigger will not be deleted from
the source system. The recording of changes would continue and the related information would be stored
in the related logging tables in the source system.
If tables are suspended for a long time the size of logging tables may increase and adjust the table space if
required.
Resume: This restarts the application for a suspended table. The previous suspended replication will be
resumed (no new initial load required).
20. If the replication is suspended for a long period of time or system outage of SLT or
HANA system what would happen?
The size of the logging tables increases.
21. How can unnecessary logging information from being stored be avoided?
Unnecessary logging information storage can be avoided by pausing the replication which is by stopping
the schema-related jobs.
22. Are the table size in SAP HANA database and in the source system the same?
No they are not same as HANA database supports compression.
23. When is table partitioning opted?
If the table size in HANA database exceeds 2 billion records, the table should be splitted by using
portioning features by using “Advanced replication settings” (transaction IUUC_REPL_CONT, tab page
IUUC_REPL_TABSTG).
24. Where are transformation rules defined?
Transformation rules are defined by using “Advanced replication settings” (transaction
IUUC_REPL_CONT, tab page IUUC ASS RULE MAP)
25. If the source system is non-SAP system, are there any special considerations?
The trigger-based replication concept is actually meant for SAP source systems. The main differences are
as below :
a) There would be a database connection between non-SAP source and SLT system instead of RFC.
b) Source must have primary key
c) Tables DD02L, DD02T which contains metadata are just initially loaded but not replicated.
d) The read modules resides on SLT system.
e) Tables with database specific formats may need transformation rules just before they are replicated.
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f) Only SAP supported databases (with respective DBSL for SAP Net Weaver 7.02) are supported as nonSAP source systems.
26. State the potential issues in the creation of a configuration?
The most potential issues in the configuration creation is the missing add-on DMIS_2010 in source
system, missing the proper role of SAP_IUUC_REPL_REMOTE for RFC user
( SAP_IUUC_USER for SLT system ) and if the Logon credentials are not correct
27. How is it ensured that data is consistent in source system and HANA system?
Since any changes in the source system that occurs is tracked in the dedicated logging tables, the
replication status for each changed data record will be transparent. An entry of logging table is deleted
after an every successful commit statement from HANA database and this procedure ensures the data
consistency between source system and HANA system.
28. Does SLT for SAP HANA support data compression like SAP HANA database?
Yes SLT for SAP HANA supports data compression like SAP HANA database and this is automatically
covered by the RFC connection used for data replication from the SAP sour.
29. What are the product names in SAP HANA?
In short answer it's a mystery. A lot of changes have happened around SAP and now it’s called SAP HANA
Appliance, SAP HANA Database and SAP HANA Studio. All applications built on HANA will be marked
"powered by SAP HANA". And this is probably to be changed again.
30. What is SAP HANA Appliance 1.0?
SAP HANA 1.0 is an analytics appliance which consists of certified hardware, and In Memory DataBase
(IMDB), an Analytics Engine and some tooling for getting data in and out of HANA. The logic and
structures are built by the user and a tool is used e.g. SAP BusinessObjects, to visualize or analyze data.
31. State the limitations of HANA 1.0?
The limitations are very less. It can only replicate certain data from certain databases and in certain
formats using the Sybase Replication Server. The Batch loading is done using SAP BusinessObjects Data
Services 4.0 and is optimized only for SAP Business Objects BI 4.0 reporting.
32. What is SAP HANA 1.5, 1.2 or 1.0 SP03?
They are all the same thing, and 1.0 SP03 is touted to be the final name which should go into RampUp
(beta) in Q4 2011. This allows 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 even
more performance gains can be attained.
33. Differentiate 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 use the SAP IMDB Database Technology (SAP HANA Database) as their
underlying RDBMS. SAP can be expected to start to differentiate this more clearly as it starts to position
the technology for use cases other than Analytics.
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34. If NetWeaver BW can be run on IMDB/HANA, why can't the Business Suite/ERP 6.0 be
run too?
This is because it's not mature enough to support business critical applications. From a technology
perspective, it is anyways possible to run the Business Suite on IMDB and SAP has trialed moving some
large databases into IMDB already.
35. What is HANA excellent at?
The most important thing to note is, 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. Demos show hundreds of
billions of records of data being aggregated in a matter of seconds. Hence SAP has built a set of Analytics
Apps on top of HANA and these are set to be great point use cases to get customers up and running
quickly.
36. What is HANA not good at?
Some current issues have been notices around HANA when delivering ad-hoc analytics, especially when
using the SAP BusinessObjects Webi tool. No doubt that the problem is that one can ask computationally
very difficult questions with Webi, which causes very long response times with HANA. SAP needs to build
optimization for both Webi and HANA to reduce the computational complexity of these questions.
37. What is the cost of HANA?
The licensing cost of HANA is not confirmed b SAP but the hardware is somewhere around $1-200k per
TB. In addition to these licensing costs this is still being made on a per-customer basis.
38. What is the reason for the speed of HANA?
The information can be retrieved from Regular RDBMS technologies put the information on spinning
plates of iron (hard disks). The information is stored in electronic memory, which is some 50x faster
(depending on how you calculate). It stores a copy on magnetic disk, in case of power failure or the like.
Also to add in, most SAP systems have the database on one system and a calculation engine on another,
and the information is passed between them. With HANA, this all happens within the same machine.
39. Is Oracle replaced by HANA/IMDB?
Once the Business Suite runs on IMDB, Oracle will not be needed form any more by SAP customers who
purchase HANA. The short term is not affected because even if HANA is bought today it still needs an
Oracle ERP system.
40. State the 10:1 compression with HANA when compared to Oracle?
When a typical uncompressed Oracle or Microsoft SQL Server database is put into HANA, it will be 10x
smaller than before and this is because of the way that HANA stores information in a compressed
format. Most databases are now compressed and these numbers may not fit every scenario, and to add to
this 2x the RAM as your database is needed including a plus room for growth. Sizing of HANA is still a
dark art.
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41. What is meant by “buy a HANA only 2.5x smaller than my big Oracle RDBMS”? How
about archiving and data ageing?
In some instances HANA appliance that is only 2.5x smaller than it would be under Oracle and only this
can be bought. Data ageing is not a part of the 1.0 release, but SAP is certainly working on it.
42. What's the extended market opportunity for IMDB?
A few analysts seem to have tapped on that the wider market opportunity which is believed to be huge.
Not only SAP applications but any third party that requires ultra-high speed. It’s not just an appliance but
a development platform.
43. What hardware is supported in SAP HANA right now?
All of the major vendors e.g. HP, IBM, Dell, are offering HANA now. Technically HANA will run on any
Intel x64 based system from your laptop through to the big 40-core, 2TB RAM servers. It is however only
supported on a small number of big rack-mount servers like the Dell R910 and HP DL980.
44. Does HANA run on blades? If not why?
It's still not clear but probably because the blades doesn’t yet offer the same performance. HANA is
optimized for the Intel X7560 CPU and runs fastest on this. For instance, the Dell M910 blade can only
run 2x X7650 CPUs and 512Gb RAM in this configuration, which probably explains the limitations. One
thing is sure that HANA will eventually run on blades as it's born to run on blade technology.
45. CAN SAP make their own IMDB/HANA hardware?
It can but only in the labs so far. No such public plans to compete against IBM/HP/Dell is there in this
space, but it could make sense for SAP to enter the appliance market, especially in the context of Data
Centers and even more so in the context of the SAP Business by Design cloud offering, which will run on
IMDB.
46. How big does HANA scale?
Theory wise at least very well. Most mid-size workloads - 2TB of in-memory storage is equivalent to 520TB of Oracle storage can be run by the biggest single server HANA hardware. HANA works in a way
that means it is possible to chain multiple systems together which means that scalability has thus-far been
determined by the size of customers' wallets. Whilst SAP talk up "Big Data" quite a lot, HANA currently
only scales to the small-end of Big Data referring to the kind of huge datasets that FaceBook or Google
have to store - not Terabytes, but rather Petabytes.
47. HANA uses which storage subsystem?
A shared network attached and varies from vendor to vendor and is called the storage. Here both regular
magnetic disks and SSD storage can be used for the backup of the database (HANA runs in memory
remember, so disk storage is just for backup, and later, for data ageing). If the operator require 2x storage
that you have RAM, which is 2x the database size - i.e. storage size = 4x database size. Anyways in most
cases there is additional ultra-high speed SSD storage for log files.
48. HANA support in real-time what types of source database?
If Sybase Replication Server (SRS) for near real-time data is used then the licensing still (SAP have license
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deals pending) needs to checked. If DB2 is run then its fine but with Oracle and Microsoft SQL Server
there are some license challenges. So if license is bought through SAP, because you may have a limited
license that does not allow extraction.
49. For batch loads what source databases does HANA support?
If SAP BusinessObjects Data Services 4.0 is used for bulk loads then it would be the best. BO-DS is a very
flexible Extract, Transform & Load tool that can support many databases
50. What additional limitations does Sybase Replication Server present?
SRS has additional restrictions which are worth to be understood. It only replicates Unicode data and
does not support IBM DB2 compress tables.
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1. State the different types of replication techniques?
The three types are as below:
ETL based replication using BODS
Trigger based replication using SLT
Extractor based data acquisition using DXC
2. What is SLT?
The full form of SLT is SAP Landscape Transformation which is nothing but a trigger based replication. It
is the replication technology to pass the data from the source system to the target system. Here the source
can be either SAP or non-SAP whereas the Target system is SAP HANA system which contains HANA
database.
3. Can we load and replicate data from one source system to multiple target database
schemas of HANA system?
Yes. It can be loaded and replicated for up to 4.
4. Can the type of data load and replication be specified?
It can be either in real time, or scheduled by time or by interval.
5. Define Configuration in SLT?
The information required to create the connection between the source system, SLT system, and the SAP
HANA system is specified within the SLT system as a Configuration. A new configuration in Configuration
& Monitoring Dashboard (transaction LTR) can hence be defined.
6. Is there any need of pre-requisite before creating the configuration and replication?
DMIS add-on is installed in SLT replication server for SAP source systems. The role
IUUC_REPL_REMOTE is assigned to the user for RFC connection but not DDIC. DMIS add-on is not
required and grants a database user sufficient authorization for data replication for a non-SAP source
system.
7. Define what is Configuration and Monitoring Dashboard?
They are applications that run on SLT replication server to specify configuration information (such as
source system, target system, and relevant connections) so that data can be replicated. The replication
status (transaction LTR) can also be monitored.
Status Yellow occurs due to triggers which are not yet created successfully.
Status Red occurs if master job is aborted (manually in transaction SM37).
8. What is advanced replication settings?
Advanced Replication settings is a transaction that runs on SLT replication server to specify advanced
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replication settings like modifying target table structures, specifying performance optimization settings
that defines transformation rules.
9 Define Latency?
Latency is the length of time to replicate data (a table entry) from the source system to the target system.
10. What is logging table?
A logging table in the source system that can record any changes to a table that is being replicated. This
thereby ensures that SLT replication server can replicate these changes to the target system.
11. What are Transformation rules?
Transformation rule is a rule specified in the Advanced Replication settings transaction for source tables
such a way that the data is transformed during the replication process. For example one can specify rule to
Convert fields, Fill empty fields and Skip records
12. When a new configuration is set up what happens?
The database connection is automatically created along with GUID and Mass transfer id (MT_ID).
Configurations with the same schema name can be created which is ensured by schema GUID.
The naming of SLT jobs and the system can uniquely identify a schema where the Mass transfer ID is
used.
13. What are the factors that influence the change/increase the number of jobs?
The factors that influence the change or increase in the number of jobs are number of configurations
managed by the SLT replication server, number of tables to be loaded/ replicated for each configuration,
expected speed of initial load, expected replication latency time. As a thumb rule, one BDG job should be
used for each 10 tables in replication to achieve acceptable latency times.
14. When is the number of Data Transfer jobs changed?
The number of data Transfer jobs changes when the speed of the initial load/replication latency time is
not satisfactory, if SLT replication server has more resources than that is initially available. The number of
initial load jobs may be reduced after the completion of the initial load
15. Mention the jobs involved in replication process?
The main jobs involved in the replication process are stated as below:
Master Job (IUUC_MONITOR_<MT_ID>)
Master Controlling Job (IUUC_REPLIC_CNTR_<MT_ID>)
Data Load Job (DTL_MT_DATA_LOAD_<MT_ID>_<2digits>)
Migration Object Definition Job (IUUC_DEF_MIG_OBJ_<2digits>)
Access Plan Calculation Job (ACC_PLAN_CALC_<MT_ID>_<2digits>)
16. State the relation between the number of data transfer jobs in the configuration
settings and the available BGD work processes?
In SLT replication server each job occupies 1 BGD work processes and for each configuration, the
parameter Data Transfer Jobs would restrict the maximum number of data load job for each mass
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transfer ID (MT_ID).
At least 4 background jobs are required for a mass transfer ID requires to be available. They are One
master job , One master controller job ,At least one data load job ,One additional job either for
migration/access plan calculation/to change configuration settings in “Configuration and Monitoring
Dashboard”.
17. If the parameter set for “data transfer jobs” to 04 in a configuration “SCHEMA1”, a
mass transfer ID 001 is assigned. In such a case what jobs should be in the system?
The jobs should be 1 Master job (IUUC_MONITOR_SCHEMA1), 1 Master Controller job
(IUUC_REPL_CNTR_001_0001) and at most 4 parallel jobs for MT_ID 001
(DTL_MT_DATA_LOAD_001_ 01/~02/~03/~04)
If at the same time lots of tables are selected for load / replication, there could be a chance that there are
not enough background jobs available to start the load procedure for all tables immediately. In such a case
the number of initial load jobs can be increased, or else tables will be handled sequentially.
For tables with large volume of data the transaction “Advanced Replication Settings
(IUUC_REPL_CONT)” to further optimize the load and replication procedure for dedicated tables can be
used.
18. After the SLT replication is over what happens?
After the replication is over, the SLT replication server creates 1 user, 4 roles, 2 stored procedures and 8
tables as mentioned below:
1 User
1 Privilege
4 Roles
<REPLICATION SCHEMA>_DATA_PROV
<REPLICATION_SCHEMA>_POWER_USER
<REPLICATION_SCHEMA>_USER_ADMIN
<REPLICATION_SCHEMA>_SELECT
2 Stored procedures
RS_GRANT_ACCESS, RS_REVOKE_ACCESS
8 Tables
DD02L, DD02T, RS_LOG_FILES, RS_MESSAGES, RS_ORDER, RS_ORDER_EXT,
RS_SCHEMA_MAP, RS_STATUS
19. State the different replication scenarios?
The different replication scenarios are Load, Replicate, Stop, Suspend and Resume.
Before any application table is selected, the initial load of the tables DD02L, DD02T & DD08L must be
completed as they contain the metadata information.
Load: This starts an initial load of replication data from the source system. The complete procedure is a
one-time event. Once completed, further changes to the source system database will not be replicated.
Also for the initial load procedure, neither database triggers nor logging tables are created in the source
system. The default settings use reading type 3 (DB_SETGET) with up to 3 background jobs in parallel to
load tables in parallel or subsequently into the HANA system.
Replicate: This combines an initial load procedure and the subsequent replication procedure (real time or
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scheduled).
Before the start of initial load procedure, trigger of database and related logging table are created for each
table in the source system as well as in SLT replication server.
Stop Replication: This stops any current load or replication process of a table.
The stop function removes the database trigger and related logging tables completely. This function is
used only if you want to continue a selected table otherwise it must be initially loaded again to ensure data
consistency.
Suspend: This pauses a table from a running replication. Also the database trigger will not be deleted from
the source system. The recording of changes would continue and the related information would be stored
in the related logging tables in the source system.
If tables are suspended for a long time the size of logging tables may increase and adjust the table space if
required.
Resume: This restarts the application for a suspended table. The previous suspended replication will be
resumed (no new initial load required).
20. If the replication is suspended for a long period of time or system outage of SLT or
HANA system what would happen?
The size of the logging tables increases.
21. How can unnecessary logging information from being stored be avoided?
Unnecessary logging information storage can be avoided by pausing the replication which is by stopping
the schema-related jobs.
22. Are the table size in SAP HANA database and in the source system the same?
No they are not same as HANA database supports compression.
23. When is table partitioning opted?
If the table size in HANA database exceeds 2 billion records, the table should be splitted by using
portioning features by using “Advanced replication settings” (transaction IUUC_REPL_CONT, tab page
IUUC_REPL_TABSTG).
24. Where are transformation rules defined?
Transformation rules are defined by using “Advanced replication settings” (transaction
IUUC_REPL_CONT, tab page IUUC ASS RULE MAP)
25. If the source system is non-SAP system, are there any special considerations?
The trigger-based replication concept is actually meant for SAP source systems. The main differences are
as below :
a) There would be a database connection between non-SAP source and SLT system instead of RFC.
b) Source must have primary key
c) Tables DD02L, DD02T which contains metadata are just initially loaded but not replicated.
d) The read modules resides on SLT system.
e) Tables with database specific formats may need transformation rules just before they are replicated.
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f) Only SAP supported databases (with respective DBSL for SAP Net Weaver 7.02) are supported as nonSAP source systems.
26. State the potential issues in the creation of a configuration?
The most potential issues in the configuration creation is the missing add-on DMIS_2010 in source
system, missing the proper role of SAP_IUUC_REPL_REMOTE for RFC user
( SAP_IUUC_USER for SLT system ) and if the Logon credentials are not correct
27. How is it ensured that data is consistent in source system and HANA system?
Since any changes in the source system that occurs is tracked in the dedicated logging tables, the
replication status for each changed data record will be transparent. An entry of logging table is deleted
after an every successful commit statement from HANA database and this procedure ensures the data
consistency between source system and HANA system.
28. Does SLT for SAP HANA support data compression like SAP HANA database?
Yes SLT for SAP HANA supports data compression like SAP HANA database and this is automatically
covered by the RFC connection used for data replication from the SAP sour.
29. What are the product names in SAP HANA?
In short answer it's a mystery. A lot of changes have happened around SAP and now it’s called SAP HANA
Appliance, SAP HANA Database and SAP HANA Studio. All applications built on HANA will be marked
"powered by SAP HANA". And this is probably to be changed again.
30. What is SAP HANA Appliance 1.0?
SAP HANA 1.0 is an analytics appliance which consists of certified hardware, and In Memory DataBase
(IMDB), an Analytics Engine and some tooling for getting data in and out of HANA. The logic and
structures are built by the user and a tool is used e.g. SAP BusinessObjects, to visualize or analyze data.
31. State the limitations of HANA 1.0?
The limitations are very less. It can only replicate certain data from certain databases and in certain
formats using the Sybase Replication Server. The Batch loading is done using SAP BusinessObjects Data
Services 4.0 and is optimized only for SAP Business Objects BI 4.0 reporting.
32. What is SAP HANA 1.5, 1.2 or 1.0 SP03?
They are all the same thing, and 1.0 SP03 is touted to be the final name which should go into RampUp
(beta) in Q4 2011. This allows 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 even
more performance gains can be attained.
33. Differentiate 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 use the SAP IMDB Database Technology (SAP HANA Database) as their
underlying RDBMS. SAP can be expected to start to differentiate this more clearly as it starts to position
the technology for use cases other than Analytics.
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34. If NetWeaver BW can be run on IMDB/HANA, why can't the Business Suite/ERP 6.0 be
run too?
This is because it's not mature enough to support business critical applications. From a technology
perspective, it is anyways possible to run the Business Suite on IMDB and SAP has trialed moving some
large databases into IMDB already.
35. What is HANA excellent at?
The most important thing to note is, 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. Demos show hundreds of
billions of records of data being aggregated in a matter of seconds. Hence SAP has built a set of Analytics
Apps on top of HANA and these are set to be great point use cases to get customers up and running
quickly.
36. What is HANA not good at?
Some current issues have been notices around HANA when delivering ad-hoc analytics, especially when
using the SAP BusinessObjects Webi tool. No doubt that the problem is that one can ask computationally
very difficult questions with Webi, which causes very long response times with HANA. SAP needs to build
optimization for both Webi and HANA to reduce the computational complexity of these questions.
37. What is the cost of HANA?
The licensing cost of HANA is not confirmed b SAP but the hardware is somewhere around $1-200k per
TB. In addition to these licensing costs this is still being made on a per-customer basis.
38. What is the reason for the speed of HANA?
The information can be retrieved from Regular RDBMS technologies put the information on spinning
plates of iron (hard disks). The information is stored in electronic memory, which is some 50x faster
(depending on how you calculate). It stores a copy on magnetic disk, in case of power failure or the like.
Also to add in, most SAP systems have the database on one system and a calculation engine on another,
and the information is passed between them. With HANA, this all happens within the same machine.
39. Is Oracle replaced by HANA/IMDB?
Once the Business Suite runs on IMDB, Oracle will not be needed form any more by SAP customers who
purchase HANA. The short term is not affected because even if HANA is bought today it still needs an
Oracle ERP system.
40. State the 10:1 compression with HANA when compared to Oracle?
When a typical uncompressed Oracle or Microsoft SQL Server database is put into HANA, it will be 10x
smaller than before and this is because of the way that HANA stores information in a compressed
format. Most databases are now compressed and these numbers may not fit every scenario, and to add to
this 2x the RAM as your database is needed including a plus room for growth. Sizing of HANA is still a
dark art.
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41. What is meant by “buy a HANA only 2.5x smaller than my big Oracle RDBMS”? How
about archiving and data ageing?
In some instances HANA appliance that is only 2.5x smaller than it would be under Oracle and only this
can be bought. Data ageing is not a part of the 1.0 release, but SAP is certainly working on it.
42. What's the extended market opportunity for IMDB?
A few analysts seem to have tapped on that the wider market opportunity which is believed to be huge.
Not only SAP applications but any third party that requires ultra-high speed. It’s not just an appliance but
a development platform.
43. What hardware is supported in SAP HANA right now?
All of the major vendors e.g. HP, IBM, Dell, are offering HANA now. Technically HANA will run on any
Intel x64 based system from your laptop through to the big 40-core, 2TB RAM servers. It is however only
supported on a small number of big rack-mount servers like the Dell R910 and HP DL980.
44. Does HANA run on blades? If not why?
It's still not clear but probably because the blades doesn’t yet offer the same performance. HANA is
optimized for the Intel X7560 CPU and runs fastest on this. For instance, the Dell M910 blade can only
run 2x X7650 CPUs and 512Gb RAM in this configuration, which probably explains the limitations. One
thing is sure that HANA will eventually run on blades as it's born to run on blade technology.
45. CAN SAP make their own IMDB/HANA hardware?
It can but only in the labs so far. No such public plans to compete against IBM/HP/Dell is there in this
space, but it could make sense for SAP to enter the appliance market, especially in the context of Data
Centers and even more so in the context of the SAP Business by Design cloud offering, which will run on
IMDB.
46. How big does HANA scale?
Theory wise at least very well. Most mid-size workloads - 2TB of in-memory storage is equivalent to 520TB of Oracle storage can be run by the biggest single server HANA hardware. HANA works in a way
that means it is possible to chain multiple systems together which means that scalability has thus-far been
determined by the size of customers' wallets. Whilst SAP talk up "Big Data" quite a lot, HANA currently
only scales to the small-end of Big Data referring to the kind of huge datasets that FaceBook or Google
have to store - not Terabytes, but rather Petabytes.
47. HANA uses which storage subsystem?
A shared network attached and varies from vendor to vendor and is called the storage. Here both regular
magnetic disks and SSD storage can be used for the backup of the database (HANA runs in memory
remember, so disk storage is just for backup, and later, for data ageing). If the operator require 2x storage
that you have RAM, which is 2x the database size - i.e. storage size = 4x database size. Anyways in most
cases there is additional ultra-high speed SSD storage for log files.
48. HANA support in real-time what types of source database?
If Sybase Replication Server (SRS) for near real-time data is used then the licensing still (SAP have license
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deals pending) needs to checked. If DB2 is run then its fine but with Oracle and Microsoft SQL Server
there are some license challenges. So if license is bought through SAP, because you may have a limited
license that does not allow extraction.
49. For batch loads what source databases does HANA support?
If SAP BusinessObjects Data Services 4.0 is used for bulk loads then it would be the best. BO-DS is a very
flexible Extract, Transform & Load tool that can support many databases
50. What additional limitations does Sybase Replication Server present?
SRS has additional restrictions which are worth to be understood. It only replicates Unicode data and
does not support IBM DB2 compress tables.
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