Connecting to a distributed relational database

 

What makes a distributed relational database application distributed is its ability to connect to a relational database on another system. There are two types of CONNECT statements with the same syntax but different semantics:

• CONNECT (Type 1) is used for remote unit of work.

• CONNECT (Type 2) is used for distributed unit of work.

For embedded SQL applications, the RDBCNNMTH parameter on the CRTSQLxxx commands determines the type of CONNECT. CLI and Java™ applications always use distributed unit of work because of the nature of the language.

• Remote unit of work
  The remote unit of work facility provides for the remote preparation and processing of SQL statements.

• Distributed unit of work
  The application-directed distributed unit of work facility also provides for the remote preparation and execution of SQL statements in the same fashion as remote unit of work.

• Implicit connection management for the default activation group
  The application requester can implicitly connect to an application server.

• Implicit connection management for nondefault activation groups
  The application requester can implicitly connect to an application server.

• Explicit connection management
  The CONNECT statement is used to explicitly connect an application requester (AR) to an identified application server (AS). This SQL statement can be embedded within an application program or you can issue it using interactive SQL.

 

Parent topic:

Programming considerations for a distributed relational database application

 

Related reference

Distributed relational database statements