Oracle provide a flexible relational database management system (RDBMS) called Oracle Database and has below key features.
- Store and manage data
- Support relational structure and PL/SQL
- Ability to store and execute program units
- Support Java and XML
- Optimize technique to retrieve data
- Secure on accessing and using the database
- Locking mechanism to protect the data in consistent way
- Integrated, comprehensive and open methodology to manage the information
Oracle server consists of Oracle database and Oracle server instance. A system global area (SGA) will allocate the memory to share the database information to users and Oracle backend processes start running when Oracle database is started, and whole integration is called Oracle Instance.
Oracle server supports American National Standards Institute (ANSI) and International Standards Organization (ISO) standard SQL for relational database. SQL (structured query language) is the programming language used to communicate with the database server to access, control, manipulate, and define the data.
A relational database contain one or more tables, and table is the basic storage structure of an RDBMS, and usually has the primary keys and foreign keys to link the multiple tables for data consistency.
In Summary, the below SQL statements are commonly used to communicate with an RDMBS, Oracle database.
| SQL Statements | Remarks |
| SELECT INSERT UPDATE DELETE MERGE | This is called data manipulation language (DML). To use for data retrieving, put in new data, change the data value, remove the data, and sync the data. |
| CREATE ALTER RENAME TRUNCATE COMMENT | This is called data definition language (DDL). To setup, change, remove, and describe the data structures for the tables. |
| GRANT REVOKE | This is called data control language (DCL). For administration used to control the access right for the database and structures. |
| COMMIT ROLLBACK SAVEPOINT | To be used together with DML statement to confirm or manage in group of logical transactions. |
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