SQL

SQL (ⁱ/ˈɛs kjuː ˈɛl/, or ⁱ/ˈsiːkwəl/;Structured Query Language) is a special-purpose programming language designed for managing data held in a relational database management system (RDBMS), or for stream processing in a relational data stream management system (RDSMS).

Originally based upon relational algebra and tuple relational calculus, SQL consists of a data definition language, data manipulation language, and a data control language. The scope of SQL includes data insert, query, update and delete, schema creation and modification, and data access control. Although SQL is often described as, and to a great extent is, a declarative language (4GL), it also includes procedural elements.

SQL was one of the first commercial languages for Edgar F. Codd's relational model, as described in his influential 1970 paper, "A Relational Model of Data for Large Shared Data Banks." Despite not entirely adhering to the relational model as described by Codd, it became the most widely used database language.

PL/SQL

PL/SQL (Procedural Language/Structured Query Language) is Oracle Corporation's procedural extension for SQL and the Oracle relational database. PL/SQL is available in Oracle Database (since version 7), TimesTen in-memory database (since version 11.2.1), and IBM DB2 (since version 9.7). Oracle Corporation usually extends PL/SQL functionality with each successive release of the Oracle Database.

PL/SQL includes procedural language elements such as conditions and loops. It allows declaration of constants and variables, procedures and functions, types and variables of those types, and triggers. It can handle exceptions (runtime errors). Arrays are supported involving the use of PL/SQL collections. Implementations from version 8 of Oracle Database onwards have included features associated with object-orientation. One can create PL/SQL units such as procedures, functions, packages, types, and triggers, which are stored in the database for reuse by applications that use any of the Oracle Database programmatic interfaces.

Oracle Database

Oracle Database (commonly referred to as Oracle RDBMS or simply as Oracle) is an object-relational database management system produced and marketed by Oracle Corporation.

Larry Ellison and his two friends and former co-workers, Bob Miner and Ed Oates, started a consultancy called Software Development Laboratories (SDL) in 1977. SDL developed the original version of the Oracle software. The name Oracle comes from the code-name of a CIA-funded project Ellison had worked on while previously employed by Ampex.

Physical and logical structures

An Oracle database system—identified by an alphanumeric system identifier or SID—comprises at least one instance of the application, along with data storage. An instance—identified persistently by an instantiation number (or activation id: SYS.V_$DATABASE.ACTIVATION#)—comprises a set of operating-system processes and memory-structures that interact with the storage. (Typical processes include PMON (the process monitor) and SMON (the system monitor).) Oracle documentation can refer to an active database instance as a "shared memory realm".

Oracle

In classical antiquity, an oracle was a person or agency considered to provide wise counsel or prophetic predictions or precognition of the future, inspired by the gods. As such it is a form of divination.

Description

The word oracle comes from the Latin verb ōrāre "to speak" and properly refers to the priest or priestess uttering the prediction. Interestingly the word Oraculum can be considered as two Arabic words joined and spoken as one: ( أورى ) Ori and ( كلم) culum. It refers to: speaking words in an unclear codified way. Similarity occurs between that meaning and the mysterious speaking style of those known as Oracles, whether in literature, movies, or else where. In extended use, oracle may also refer to the site of the oracle, and to the oracular utterances themselves, called khrēsmoi (χρησμοί) in Greek.

Oracles were thought to be portals through which the gods spoke directly to people. In this sense they were different from seers (manteis, μάντεις) who interpreted signs sent by the gods through bird signs, animal entrails, and other various methods.

SQL Developer

SQL Developer may refer to: