Transferring Data Using DB Connect
By default, when the BW application server starts, SAP kernel opens a connection to the database on which the SAP system is running. In the remainder of this section, this connection is referred to as the (SAP) default connection. All SQL commands that are submitted by the SAP kernel or ABAP programs (irrespective of whether they are open or native SQL commands), automatically refer to this default connection; they run in the context of the database transaction that is active in this connection. Connection data, such as database user name, user password, or database name are taken either from the profile parameters or from the corresponding environment variables (this is database specific).
DB Connect enables you to open other database connections for supported relational database management systems, in addition to the default connection, and use these connections to transfer data from tables or views to a BW system. To do this, create a source for the database and make the metadata known to the source by creating a DataSource in BW.
You can still create schema-specific source systems for the default connection. In particular, this function allows you to create Open ODS views for tables or views from SAP HANA schemas.
If the BW system runs on the SAP HANA database, you can also create source systems for using SAP HANA Smart Data Access. SAP HANA Smart Data Access makes it possible to access data from remote sources as if they were local tables in SAP HANA, without replicating data to SAP HANA. Supported remote sources include SAP SAP IQ (versions 15.4 ESD#3 and 16) or SAP HANA SPS06 or higher.
If you want to create a connection to an external database, you need relevant knowledge and experience of the source database in the following areas:
- Tools
- Database-specific SQL syntax
- Database-specific functions
You also need relevant knowledge of the source application, so that you can transfer semantically usable data into BW.
If the BW DBMS and the source DBMS are different, you have to install a database-specific DB client for the respective source-database management system (DBMS) on the BW application server before you can use the DB Connect functions.
You need to license the database-specific DB client with the database manufacturer. You can get information about the database-specific DB client from the respective database manufacturers.
In addition, the SAP-specific part of the database interface - the Database Shared Library (DBSL) - must be installed for the corresponding source database management system on the BW application server. For more information, see Installing the Database Shared Library (DBSL).
The information contained in the DB Connect documentation is subject to change. Always refer to the SAP Notes listed in the documentation.
A purchasing application runs on a system that is based on a DBMS X. Before you can analyze the data in the purchasing application, the data must be loaded into a BW system that is based on a DBMS Y. DBMS Y can be the same as DBMS X or it can be different to DBMS X. If DBMS Y is the same as DBMS X, you do not need to install the database-specific client and the database-specific DBSL. DB Connect allows you to connect the DBMS of the purchasing application and to extract the data from the database tables or views to transfer it into BW.