What is DCL? DCL is a shortened term for Data Connection Library. It is used primarily in Oracle database servers. If you are talking about database language, then DCL is an Oracle dialect. In this article, DCL will be discussed briefly and some pros and cons will be discussed as well.
A data control language is also a syntax similar to an ordinary computer programming language used for controlling access to information stored in a database. In short, it is also a component of Structured Query Language, abbreviated as SQL. Basically, DCL contains a set of generic functions and operators that are implemented as queries in an Oracle database server. Generally, DCL provides support for functions that access data without requiring the usage of stored procedures or any such intermediary steps. Data Connection Library thus enables a user to gain access to stored procedures and other features of Oracle database without the use of DCL or any other programming languages.
DCL makes DDL easier to develop and less complicated to use. With DCL, developers don’t have to create a special connection to the database or write code to manage database connections. The DCL declares information types, query operators, and functions to be accessible from within Oracle. Instead of having to write DDL statements one by one to manage different database transactions, Oracle allows developers to put together multiple DCL statements that can then be executed in an ordered way on the Oracle database server. As an example, DCL can be used to automatically increment current login information, create or reset a password for a user, or return current password.
Oracle database has a feature called Oracle Enterprise Manager or ORM. It is an embedded database management system (DBMS) based upon the Linux kernel. The ORM controls transaction log execution, controls connection information, and provides facilities such as concurrent log processing and full threading support. Through these facilities, a developer can use DCL to write DDL scripts or DCL code that can be used directly by the Oracle database server, rather than having to use separate software likeawk or pod to accomplish similar tasks.
DCL provides a flexible data connection model. One aspect is that DCL automatically creates a full context for each stored procedure or function and maintains the security of all data simultaneously. Another aspect is that DCL dynamically modifies the existing connections to make them compatible with newer versions of Oracle. Oracle also supports compact data connection models for application servers and web servers. This Compact Data Connection (CDOC) is a convenient tool for managing small data sets that require small application servers and web servers and for making transactions in more manageable chunks.
Oracle Enterprise Manager provides Oracle users with a flexible DCL implementation that can be integrated with different database server back ends. DCL code that uses the –db2ls and –multi-db features of Oracle Enterprise Manager simplifies the database server startup and configuration. The Oracle Enterprise Manager Database Interface (ORMID) also offers the –create-transactions capability and the ability to use DCL with –allow-other-dbx and –multi-user attributes of Oracle Enterprise Manager. With these options, an Oracle database server user can create transactions per DCL command and use DCL to create transaction logs.
DCL allows applications to process transactions per second (or sometimes per second) in a way that is more efficient and economical. For instance, consider the typical SQL Server transactions per second (TPS) limits for local, central, and public database servers. If they are all running on the same operating system, each of these transactions will take 100 cycles on each machine. With the –create-transactions capability of Oracle Enterprise Manager, an application can process hundreds of transactions per second from a single machine. There are other benefits of Oracle Enterprise Manager for DCL implementation.
For example, with –create-transactions and –allow-other-dbx-logs options, you can configure your DCL application to stop when a transaction is committed. This feature reduces the amount of time spent waiting for data to be available in other databases. Another benefit of Oracle Enterprise Manager DCL is the –logging option. With this feature, you can receive a list of transactions per second from your DCL application. The –logging option can reduce the server load when a large number of transactions are processed.