Purpose
Real-time data
acquisition supports tactical decision-making.
It also supports operational
reporting by allowing you to send data to the delta queue or PSA table in
real-time.
You then use a daemon to transfer DataStore objects to the
operational DataStore layer at frequent regular intervals.
The data is stored
persistently in BI.
We recommend that
you use real-time data acquisition if you want to transfer data to BI at
shorter intervals (every minute) than scheduled data transfers and you need
up-to-date data to be regularly available in reporting (several times a day,
at least).
The following
overview displays the differences between standard data acquisition using
scheduled data requests and real-time data acquisition:
Prerequisites
●
The DataSource has
to support real-time data acquisition.
Web service
DataSources and DataSources from SAP source systems can support real-time data
acquisition. In DataSource maintenance, the Extraction tab page shows whether the Real
Time property is
set.
DataSources
from SAP source systems can be used for real-time data acquisition if the
following prerequisites are met:
○
BI Content
DataSources have to be delivered with the property for supporting real-time
data acquisition.
○
The Real-Time-Enabl.indicator
has to be set in the generic delta settings for generic DataSources (more information: Delta Transfer to BI).
Note that
real-time data acquisition as a property of DataSources in SAP source systems
is only possible technically under the following circumstances:
In the source
system, the BI Service API has at least the version Plug-In-Basis 2005.1 or
for 4.6C source systems Plug-In 2004.1 SP10.
Note also
that you can only use a Web service DataSource for real-time data acquisition
if you have defined it in the (new) DataSource maintenance in BI.
●
You use a
transformation between the PSA and DataStore object and update data into
DataStore objects from the PSA using the data transfer process.
Process Flow
The following
figure illustrates the process flow for real-time data acquisition:
Data is loaded into
BI at frequent, regular intervals and is then posted to the DataStore objects
that are available for operational reporting.
In BI, special InfoPackages are
used for this purpose and data transfer processes for real-time data
acquisition are created to further process data from the PSA in the DataStore
objects.
This is scheduled and executed regularly by a dedicated background
process (the daemon).
Data is available for reporting as soon as it has been
successfully posted to the DataStore object and activated.
Refresh the query
display to display the recent data.
The query shows the time that the query
was last updated by a daemon run, even if no new data was posted.
You can transfer
data from the source to the entry layer of BI (the PSA) in two
ways:
..
●
Using a Web
service
You use the
Web service to write the data from the source into the PSA. The transfer of
data is controlled externally, without a request from BI. Only an InfoPackage
(for full upload) is required to determine specific parameters for real-time
data acquisition.
●
Using a service
API
Data from an
SAP source system can be loaded into the PSA using an InfoPackage created
specifically for this purpose. This is triggered when the delta queue in the
source system requests data. You have to simulate the initialization of the
delta process for the DataSource beforehand.
The following
two scenarios are possible:
○
The source system
application writes the data to the delta queue.
In this
case, the daemon retrieves the data without calling the extractor.
○
The application
does not write data to the delta queue automatically; the extractor writes the
data to the delta queue at the request of BI.
For
extractors that transfer data synchronously from BI to the service API on
request (generic extractors, for example), the daemon calls the extractor, and
the extractor writes the data to the delta queue. The data is transferred to
BI directly from the delta queue.
Constraints
●
You can only use
real-time data acquisition to fill DataStore objects. A two-step data transfer
is supported; data is first transferred into the PSA and then into the
DataStore object. The DataStore object cannot be used as the source for a
further real-time data transfer to another DataStore object.
●
Master data cannot
be transferred to the BI system with real-time data acquisition as otherwise
the navigation attributes of the characteristic could no longer be used in
aggregates. This is because aggregates cannot react to real-time updates since
the change run in the RDA process cannot be triggered automatically for the
loaded data.
●
DataSources that
are used for real-time data acquisition cannot be used in the delta process
for standard data transfer (scheduled staging).
A data transfer with RDA and a
scheduled data transfer cannot be executed simultaneously in the delta process
for a DataSource because there may be only one entry in the delta queue for
each DataSource and target system.
In addition
to a pure RDA update and a pure standard update, the following update methods,
in which both transfer mechanisms are used in parallel, are possible for data
that was transferred to the PSA by real-time data acquisition:
The data is
updated from the PSA to a DataStore object with a DTP for real-time data
acquisition, and to another DataStore object with a standard DTP.
●
If you load data
into a DataStore object with real-time data acquisition, you cannot load data
into this DataStore object simultaneously with an additional DTP. This is
because there can be only one open activation request in a DataStore object.
Real-time data acquisition keeps an activation request open parallel to each
DTP request. In a DTP request, multiple data packages can be loaded during a
given time span. Each data package is activated in the DataStore object
immediately after it is transferred. A further data transfer process cannot
load into the same DataStore object as long as an activation request is
open.
Depending on
the requirements, you can nevertheless merge the data that you load with a
real-time data acquisition in an InfoProvider with additional data
sources.
○
The DataStore
object in which you load data with real-time data acquisition can be used in a
MultiProvider or InfoSet.
○
Using a process
chain, you can restrict the time in which you load data into the DataStore
object with real-time data acquisition. You can load data into the same
DataStore object with a different data transfer process during the remainder
of the time.
More
information:
Converting an Existing Data Flow to Real-Time Data Acquisition
If you want to
integrate the transfer of data with real-time data acquisition into an
existing data flow, you have two options:
●
Using two different
DataSources
One
DataSource executes the standard data transfer. The other DataSource transfers
the data with real-time data acquisition. The data is then combined in a
MultiProvider.
●
Using a single
DataSource
You have to
replace the standard data transfer completely with a real-time data
acquisition scenario.
More information:
Real-Time Data
Acquisition
Real-Time Data
Acquisition
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