Since a DataStore object
is designed like a table, it contains key fields (document number and
item, for example) and data fields. Data fields can not only be key
figures but also character fields (order status, customer, or time, for
example). You can use a delta update to update DataStore object data
into connected InfoCubes or into additional DataStore objects or master
data tables (attributes or texts) in the same system or in different
systems. In contrast to multidimensional DataStores for InfoCubes, data
in DataStore objects is stored in flat, transparent database tables.
Fact and dimension tables are not created.
With DataStore objects, you can
not only update key figures cumulatively, as with InfoCubes, but also
overwrite data fields. This is especially important for
transaction-level documents that change in the source system. Here,
document changes not only involve numerical fields, such as order
quantities, but also non-numerical ones such as ship-to parties,
delivery date, and status. Since the OLTP system overwrites these
records when changes occur, DataStore objects must often be moceled to
overwrite the corresponding fields and update to the current value in
BI.
DS Oject Types
SAP BI distinguishes between three
DataStore object types: Standard, Write Optimized, and Direct Update.
These three flavors of DataStore Objects are shown in the following
figure.
1. The Standard DataStore Object
consists of three tables (activation queue, active data table, and
change log). It is completely integrated in the staging process. In
other words, data can be loaded into and out of the DataStore Objects
during the staging process. Using a change log means that all changes
are also written and are available as delta uploads for connected data
targets.
Architecture and Functions of Standard DataStore Objects
Architecture and Functions of Standard DataStore Objects
Standard DataStore objects consist of three tables:
Active Data table
This
is where the current status of the data is stored. This table contains a
semantic (business-related) key that can be defined by the modeler
(order number, item, or schedule line, for example). It is very
important that the key be correctly defined by the modeler, as a match
on the key initiates special delta processing during the activation
phase (discussed later). Also, reporting via the BEx uses this table.
Change Log table
During the activation run, changes are stored in the
change log. Here, you can find the complete history of the changes,
since the content of the change log is not automatically deleted. The
connected targets are updated from the change log if they are supplied
with data from the DataStore object in the delta method. The change log
is a PSA table and can also be maintained in the PSA tree of the Data
Warehousing Workbench. The change log has a technical key consisting of a
request, data package, and data record number.
Activation Queue table
During
the DTP, the records are first written to this table. This step is
necessary due to the complex logic that is then required by the
activation process.
Schema for a Standard DataStore Objects
2. Write optimized is a new kind of DataStore Object . It is targeted for the warehouse level of the architecture, and has the advantage of quicker loads.
3. A direct update DataStore object
(previous 3.x transactional ODS) has only the table with active data.
This means it is not as easily integrated in the staging process.
Instead, this DataStore object type is filled using APIs and can be read
via a BAPI.
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