Defined object used to store or reference data
A database object is a structure for storing, managing and presenting application- or user-specific data in a database. Depending on the database management system (DBMS), many different types of database objects can exist.[1][2] The following is a list of the most common types of database objects found in most relational databases (RDBMS):
- Tablespace, storage space for tables in a database
- Tables, a set of values organized into rows and columns
- Indexes, a data structure providing faster queries (at the expense of slower writing and storage to maintain the index structure)
- Views, a virtual table that is made as it is queried
- Synonyms, alternate names for a table, view, sequence or other object in a database
- Stored procedures and user-defined functions
- Triggers, procedures which are run automatically based on specific events
- Constraints, a constraint on the domain of an attribute
- User accounts, schemas and permissions
Database objects are permanent,[3] which means that they remain in their form as long as they are not explicitly changed or deleted. Application- or user-specific database objects in relational databases are usually created with data definition language (DDL) commands, which in SQL for example can be CREATE
, ALTER
and DROP
.[4][5]
Rows or tuples from the database can represent objects in the sense of object-oriented programming, but are not considered database objects.[6]
References
- ^ "Database Objects". docs.oracle.com (SQL Language Reference). Oracle. Retrieved 2023-07-05.
- ^ Randolph West; et al. (2023-05-23). "sys.all_objects (Transact-SQL)". Microsoft. Retrieved 2023-07-05.
- ^ Sprachen für Datenbanken. Informatik-Fachberichte. Vol. 72. 1983. p. 185. doi:10.1007/978-3-642-69297-0. ISBN 978-3-540-12733-8 – via link.springer.com.
- ^ Rahul Awati (June 2022). "Data Definition Language (DDL)". techtarget.com. TechTarget. Retrieved 2023-07-10.
- ^ "Generating DDL statements for database objects". ibm.com (DB2 Version 9.7 for Linux, UNIX, and Windows). International Business Machines Corporation. 2021-03-01. Retrieved 2023-07-10.
- ^ Relationale Datenbanken und SQL in Theorie und Praxis. EXamen.press. 2012. p. 41. doi:10.1007/978-3-642-28986-6. ISBN 978-3-642-28985-9 – via link.springer.com.