Sybase 12.4.2 manual Benefits of procedures, Introduction to procedures, 230

Benefits of procedures

Benefits of procedures

	Procedures are defined in the database, separate from any one database
	application. This separation provides a number of advantages.
Standardization	Procedures allow standardization of any actions that are performed by more
	than one application program. The action is coded once and stored in the
	database. The applications need only call the procedure to achieve the desired
	result. If the implementation of the action evolves over time, any changes are
	made in only one place, and all applications that use the action automatically
	acquire the new functionality.
Efficiency	When used in a database implemented on a network server, procedures are
	executed on the database server machine. They can access the data in the
	database without requiring network communication. This means that they
	execute faster and with less impact on network performance than if they had
	been implemented in an application on one of the client machines.
	When a procedure is created, it is checked for correct syntax and then stored in
	the system tables. The first time it is required by any application, it is retrieved
	from the system tables and compiled into the virtual memory of the server, and
	executed from there. Subsequent executions of the same procedure will result
	in immediate execution, since the compiled copy is retained. A procedure can
	be used concurrently by several applications and recursively by one
	application. Only one copy is compiled and kept in virtual memory.
Security	Procedures, including user-defined functions, execute with the permissions of
	the procedure owner but can be called by any user that has been granted
	permission to do so.
	This means that a procedure can (and usually does) have different permissions
	than the user ID that invoked it. Procedures provide security by allowing users
	limited access to data in tables that they cannot directly examine or modify.

Introduction to procedures

In order to use procedures, you need to understand how to do the following:

•Call procedures from a database application

•Create procedures

•Drop, or remove, procedures

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