Database Reference
In-Depth Information
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Threads
Incoming HTTP requests from the browser are accepted by thread control
and then passed to the worker thread.
•
Memory pipes
Help transfer data between the ICM worker thread and ABAP work
process.
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Connection info
Table with network connections information.
•
Watch dog
Frees up the waiting worker thread from timed-out connections and passes
the information back to the worker thread when it eventually receives it for process-
ing.
•
Signal handler
Processes operating system and SAP dispatcher signals.
Internet Communication Framework
ICF is part of SAP standard kernel delivery. Requests sent from the ICM are forwarded to
one or more ABAP programs by ICF. Once the response is received, ICF sends the data
back to ICM and eventually to the client. ICF performs this activity in the form of standard
services. One example of such a service is the Internet Transaction Server (ITS).
Integrated ITS
Earlier SAP versions had an architecture that included an external ITS. The current version
of ITS, however, is referred to as integrated ITS. Integrated ITS is needed for some scenari-
os of SAP usage—for example, access via SAPGUI for HTML. ITS will help automatically
convert the SAP screen for the end user using SAPGUI for HTML.
• Transaction code SMICM is used to administer the ICM.
• Transaction code SICF is used to manage the ICF services.
SAP Database Tier
A relational database such as Oracle, DB2, or SQL Server, with several hundreds and thou-
sands of tables, constitutes a SAP database layer. SAP application data is stored in the data-
base tables and ABAP (Advanced Business Applications Programming) programs use Open
SQL to interact with the underlying database via a database interface. The database interface
will convert the Open SQL to native SQL. Even though SAP uses a number of different re-
lational database systems, such as Oracle, DB2, and SQL Server as a data repository, the ap-
plication logic is in the SAP data dictionary that sits on top of the database data dictionary.
Therefore, underlying relational databases have to be managed as a “SAP database” using
SAP-provided tools. It is not recommended to bypass this application layer to directly con-
nect with and manipulate the database data using native database tools. If the database data
is accessed directly without going through the application logic or SAP-provided database
