There are few options when
it comes to modeling of EDW design. SAP recommends so called Layered Scalable
Architecture (LSA). This one I covered in my post here. Such
architecture gives a guide for implementing new models in BW. Means what kind
of layers are supposed to be used for that particular model.
The (E) DW Layer consists of the first 4 layers. The
Architected DataMart Layer or BI Layer consists of the last 3 layers. Here are
reference Layers:
·
Data Acquisition Layer (DWH)
·
Harmonization & Quality Layer (DWH)
·
Corporate Memory Layer (DWH)
·
Propagation Layer (DWH)
·
Business Transformation Layer (BI)
·
Reporting Layer (BI)
·
Virtual Layer (BI)
With HANA coming into the
scope of BW which is known as BW on HANA (BoH) the LSA got renewed. Basically
also HANA optimized objects are incorporated into the architecture. Because of
nature of HANA data persistency is less needed across different layers of LSA.
This leads to reduction of the layers. Basically this new reference
architecture built for BW on HANA is called Layered Scalable Architecture (LSA++)
These are following new InfoProvider
objects incorporated into LSA++:
Open
ODS View – is object designed to consume external sources with
a given semantic. There are no InfoObjects needed to define analytic semantics.
Instead it allows field-based modeling. This is in line with agile data modeling
suitable e.g. for rapid prototyping. An analytic functionality can be employed
on top of (external) data structures due to different interfaces like SAP HANA
smart data access. External data (not residing in BW) can be combined with SAP
BW data (master and transaction data). It is virtual object – data is not
persistent. The Open ODS View object is equivalent of PSA layer in LSA.
Advanced
DataStore object (ADSO) – is standard persistent InfoProvider,
supports analytic queries, in future also planning apps, capable of calculating
data changes within data flow, consolidates different types of IProv: classic
DSO, w/o DSO, InfoCube. The consolidation of different objects can be done on
the fly by switching its behavior without deleting the data. Modeling of ADSO
is done only in Eclipse environment. The data is persistent in the ADSO.
(new) Composite Provider (ComProv) – this is meant for new composite
provider available in BW 74 on Hana not the one available in BW 7.3. The new
one is successor of MultiProv and Infosets. It is modeling object for both:
joins and unions, can consolidate existing InfoProv (VirtualProv base on SAP
HANA models, InfoSets, MultiProv, etc). Modeling of the new ComProv is done in
Eclipse environment. It fits to Virtual(ization) layer of LSA++.
More information:
LSA++ for
SAP NetWeaver BW on SAP HANA – SCN article by Juergen Haupt, EIM203 session
do you consider the "Open ODS View object is equivalent of PSA layer in LSA" the same as the Acquisition Layer as with the older LSA
ReplyDeletehi G,
ReplyDeletealthough I do not have much experience with Open ODS objects yet I would say that the Open ODS can be considered in terms of LSA++ as the same as PSA object in LSA world. The Open ODS or Open Operational Data Store Layer is LSA++'s inbound Layer or acquisition layer. It serves its purpose for operational BI, agile BI and streamlined EDW.
It also serves for real time replication if data into BW, it can be used for immediate querying acquired data as there is no staging into EDW needed. It can be used as source for persistent EDW providers.
Cheers,