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An example of a database that has not enforced referential integrity. In this example, there is a foreign key ( artist_id ) value in the album table that references a non-existent artist — in other words there is a foreign key value with no corresponding primary key value in the referenced table.
An example of a data-integrity mechanism is the parent-and-child relationship of related records. If a parent record owns one or more related child records all of the referential integrity processes are handled by the database itself, which automatically ensures the accuracy and integrity of the data so that no child record can exist without a parent (also called being orphaned) and that no ...
A database administrator (DBA) manages computer databases. [1] The role may include capacity planning , installation , configuration , database design , migration , performance monitoring, security , troubleshooting , as well as backup and data recovery .
Database administration is the function of managing and maintaining database management systems (DBMS) software. Mainstream DBMS software such as Oracle , IBM Db2 and Microsoft SQL Server need ongoing management.
It provides ODBC, JDBC, and OLE DB access to Adabas and enables SQL access to Adabas using COBOL programs. Search facilities may use indexed fields, non-indexed fields, or both. Does not natively enforce referential integrity constraints, and parent–child relations must be maintained by application code.
Entity integrity is concerned with ensuring that each row of a table has a unique and non-null primary key value; this is the same as saying that each row in a table represents a single instance of the entity type modelled by the table.
The term integrity encompasses accuracy, consistency and some aspects of validation (see also Data integrity) but is rarely used by itself in data-cleansing contexts because it is insufficiently specific. (For example, "referential integrity" is a term used to refer to the enforcement of foreign-key constraints above.)
SQL [1] is the standard language for relational database management systems. SQL statements are used to perform tasks such as insert data to a database, delete or update data in a database, or retrieve data from a database.