Linking Servers

A QUESTION CAN BE ASKED HOW TO CALL A STORED PROCEDURE OF ORACLE DATABASE FROM SQLSERVER DATABASE STORED PROCEDURE
A linked server configuration enables SQL Server to execute commands against OLE DB data sources on remote servers

Linked servers offer the following advantages:

1. Remote server access.
2. The ability to issue distributed queries, updates, commands, and transactions on heterogeneous data sources across the enterprise.
3. The ability to address diverse data sources similarly.

Typically, linked servers are used to handle distributed queries. When a client application executes a distributed query through a linked server, SQL Server parses the command and sends requests to OLE DB. The rowset request may be in the form of executing a query against the provider or opening a base table from the provider.
For a data source to return data through a linked server, the OLE DB provider (DLL) for that data source must be present on the same server as the instance of SQL Server.
When a third-party OLE DB provider is used, the account under which the SQL Server service runs must have read and execute permissions for the directory, and all subdirectories, in which the provider is installed.