SAP BW NLS- Frequently Asked Questions
Q: Can I archive data from a BW InfoProvider that has no time characteristic included?
In BW on HANA it is not possible to archive data in an InfoProvider that has no time characteristics / date field at all. There, it is currently not possible to select the flag “Free selection for archiving” in the Data Archiving Process. In BW/4HANA it is possible to select an arbitrary key characteristic/field as primary partitioning characteristic/field even if no time characteristic/field exists within the Advanced DataStore Object. In this case mode “Free selection for archiving” is selected automatically and additional partitioning characteristics/fields from the key can be added optionally.
Q: Do input value helps in BW Queries display data from nearline storage (for setting “Only Values in InfoProvider”)
This is only possible when using Advanced DataStore Objects and SAP BW >= 7.50 SP01 in conjunction with NLS IQ on the basis of SAP HANA SDA (Smart Data Access). Please also see SAP Note 2087677 – Input help in mode “Only Values in InfoProvider” and near-line storage.
Q: Can I archive data from a BW InfoProvider that contains non-cumulative key figures?
At this time, data can’t be archived from Advanced DataStore Objects that contain non-cumulative key figures.This functionality is planned but currently not available (please refer to most current product roadmap).
Archiving data from (former) InfoCubes with non-cumulative key figures is only supported if you are using an SAP HANA database and have connected SAP IQ as a near-line solution using the adapter delivered with the BW system. The InfoCubes must be SAP HANA-optimized. For more information see:
Q: Can External Views generated for BW access Nearline Storage?
See SAP Note 2032797 – External SAP HANA view: Include NLS data with HANA Smart Data Access and SAP IQ and the SAP Help: https://help.sap.com/saphelp_nw75/helpdata/en/66/33d851345c4770bd4e523701b9f5b0/frameset.htm
Q: What is the minimum prerequisite for using Nearline Storage for Advanced DataStore Objects?
See SAP Note 2215265 – Near-line storage (NLS) for advanced DataStore object (ADSO) – Release and prerequisites
Q: Will there be duplicate records between objects stored in the NLS and BW Objects at any time?
Sybase IQ uses snapshot versioning: a write operation cannot block a read operation or vice versa. Readers will see the data valid at the beginning of their extract, even if more recent changes have been applied and committed in the meanwhile. There is a time window around the archiving process during which data exists in two identical instances (once in the primary BW DB, once in NLS). BW is be able to correctly distribute the search criteria so they are restricted that only one instance is respected.
Implementation and Change Management
Q: How do BW and NLS tables sync up again after an InfoProvider has been extended?
Adding a new field to an InfoProvider deactivates an associated Data Archiving Process (DAP). Then reactivating the DAP adds the new field to the NLS table. Please note that the added field is empty. If the added field should be filled you have to reload the data, update the new field and archive the data again. DAP activation can be included as part of the transport to adjust QA and Production systems.
Q: What kind of structural changes are permitted if BW InfoProvider has sent data to NLS already?
Please refer to http://service.sap.com/sap/support/notes/1005040.
Q: What happens when a data archiving process gets deleted in BW?
When a DAP is deleted in BW, the corresponding tables and all archiving requests are deleted from the Sybase IQ database.
Q: What happens when an InfoProvider with an associated Data Archiving Process (DAP) gets deleted?
If archiving has not been executed before, the DAP and corresponding tables from IQ will be deleted. On the other hand, if archiving has been executed previously, the DAP as well as previously archived data on Sybase IQ remain in place for future usage.
Q: What to consider when transporting Data Archive Processes and associated NLS connections?
In general you should use the same logical name for your NLS connection in all systems throughout your transport landscape pointing to the particular NLS target database (such as Sybase IQ) per system. Then you can transport the DAPs and generate the archiving requests per system. There is no automatic conversion of NLS connection names in BW transport management (like for BW source systems).
Q: Is there a way to activate several Data Arching Processes in parallel?
Please see SAP Note 2249274 – Mass activation report for DAPs
Q: Is it possible to parallelize the Data Archiving Process (DAP) in BW?
Currently the parallel processing option for DAPs is not supported at batch process level (transaction code: RSBATCH). However, there is a work around based on data modeling level: By splitting the archiving request into several data archiving processes and scheduling them in parallel in a Process Chain, it is possible to achieve parallelism. See the workaround description and SAP Note 2109015 – Continuation of Archiving Requests for Copy, Verification, and Deletion Phase in parallel.
System Operations and Monitoring
Q: How can Nearline Storage Tables and Partitions be accessed and managed from BW?
In order to access and manage partitions on Sybase IQ from BW, SAP provides the program “RSDA_SYB_PARTITION_MONITOR” which is the “Partition Monitor for Nearline Table in Sybase IQ”. This report provides a detailed overview of all Nearline Tables in Sybase IQ and the corresponding partitions for each table.
Since the number of partitions for a data table on Sybase IQ is limited to 1024, the program allows users to define threshold values in order to create alerts and monitor all critical tables which exceed the upper threshold value. In this case the report can be also used to drop or/and merge the individual partitions. See detailed example.
Please also consider the following SAP Note for introducing a new dbspace-oriented partitioning mode for SAP NLS IQ: 2190504 – BW NLS IQ: New dbspace-oriented partitioning mode.
Q: How can I check performance for NLS query access as well as how many records have been read from NLS during reporting?
You can check it with the query monitor in BW (transaction RSRT). Please enter your respective BW Query –> “Execute + Debug” –> Others > check “Display Statistics Data” (and “Do Not Use Cache” – optional). Then, you can check how many records were read from NLS and how long it took for reading form NLS.
Suffix $X reflects the active data and $N reflects Near-line Storage (Sybase IQ).
Q: Is it possible to see how much storage a partition / table needs in NLS?
Since BW/4HANA SP01 an ABAP CDS View for querying / monitoring NLS table statistics. Please see: http://help.sap.com/saphelp_bw4hana10/helpdata/de/1e/596b288f494f5d815c86cf94c3fbbb/frameset.htm.
Starting from SAP_BW 7.50 SP4 you may get similar but less enriched information from view RSDANLSTAT_V.
Q: Is it possible to display data from a Nearline Storage Table in SAP IQ from SAP BW?
Yes, this is possible by using the program RSDA_SYB_SE16. Please see SAP Note 2110887 – Native SQL access via SAP IQ Near-line Connection within SAPGUI.
System Set Up
Q: Can one NLS system connect to multiple BW instances?
Yes. One Sybase IQ server can talk to multiple BW systems. You should create separate schemas in IQ for the different BW systems. Nevertheless, with respect to backup and recovery synchronization and risk isolation it is recommended to have a dedicated IQ database instance for mission critical systems.
Q: Does the SAP NLS supports database and network encryption?
Column encryption (IQ only) – In standalone IQ can be encrypted at the column level. This is meant to protect against unwanted access to data from the database level. While you may have permissions to view a table, column encryption puts a more granular spin on it and prevents you from seeing data that you don’t have the key for. Column encryption is not part of DT and it is not supported by NLS. NLS would have to make coding changes at the application level for this to happen. The main issue here is that NLS is not just IQ, it supports any database. This would complicate column encryption because every database uses different syntax, tools, and encryption algorithms.
Database encryption – IQ has always had database encryption for standalone IQ. Database encryption protects IQ against intrusion at the storage level. In memory (like SAP HANA) the data is unencrypted, but when written to disk it goes through encryption. This is designed to protect against a user without IQ access from looking at the disks themselves. In theory, if one had access to the storage (no IQ software), one could look at the disks and rebuild the data from what one sees on disk. Whole database encryption will prevent that from happening.
For encryption of your connection to SAP IQ please refer to SAP Note 1999431 – SIQ: Setting up SSL for connections to IQ, included in First Guidance Document.
For implementation details please refer to SAP First Guidance… SAP BW: Implementation SAP-NLS/SDA with SAP IQ 16.0
Q: Can SAP IQ run in a cloud environment?
See SAP Note 2133194 – Can SAP IQ run in a cloud environment?.