To establish a linked server using the ODBC driver in SQL Server, you’ll first need to install and configure the ODBC driver on the machine with the local SQL Server. The ODBC driver facilitates data exchange and allows SQL Server to query and access the remote data as if it were located in its own environment. Setting up a linked server using the ODBC driver enables SQL Server to establish a direct connection with external data sources like Oracle databases, for example. Setting up a linked server using the ODBC driverīy configuring a linked server, you can access and query data from the remote server as if it were part of your local SQL Server instance. SQL Server then combines the result sets and returns the final result set. The local queries are executed on the local server, while the remote queries are sent to the remote server. This is because linked servers involve breaking the query into local and remote queries. In terms of performance, OPENQUERY tends to outperform linked servers.Such operations as parsing the query and generating the execution plan are carried out on the remote server. When using OPENQUERY to access remote data, SQL Server forwards the query to the remote server.Parameters in the OPENQUERY function are not supported, and it cannot be used for executing extended stored procedures on linked servers.However, if you frequently query the remote server, it is advisable to utilize linked servers instead. The OPENQUERY function is an ad-hoc method to access data from a remote server.Users should carefully consider performance implications and possible security risks before utilizing this feature. However, it is essential to exercise caution when working with OPENQUERY, as it involves network communication and might introduce additional overhead. ![]() It is particularly valuable in scenarios where data resides in separate databases, perhaps hosted on different database management systems. Using OPENQUERY, users can efficiently retrieve data from various data sources without the need for complex data migration or manual data transfers. T-SQL Query is the T-SQL code that you want to execute on the remote server. LinkedServer is the name of the linked server. The syntax for using OPENQUERY is straightforward: SELECT * FROM OPENQUERY (LinkedServer, 'T-SQL Query') Once the linked server is set up, OPENQUERY enables the execution of SQL statements on the remote server directly from within SQL Server, as if the data were local. The key concept behind OPENQUERY is the establishment of a linked server, which acts as a bridge between the local SQL Server instance and the remote data source. ![]() OPENQUERY serves as a gateway for accessing data stored on external servers, allowing SQL Server to interact with different databases across the network.
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