In
database
In computing, a database is an organized collection of data stored and accessed electronically. Small databases can be stored on a file system, while large databases are hosted on computer clusters or cloud storage. The design of databases s ...
design, a Persistent Object Identifier (POID) is a
unique identifier
A unique identifier (UID) is an identifier that is guaranteed to be unique among all identifiers used for those objects and for a specific purpose. The concept was formalized early in the development of computer science and information systems ...
of a record on a table, used as the
primary key. Important characteristics of a POID are that it does not carry business information and are not generally exported or otherwise made visible to data users; as such a POID has many of the characteristics of a
surrogate key
A surrogate key (or synthetic key, pseudokey, entity identifier, factless key, or technical key) in a database is a unique identifier for either an ''entity'' in the modeled world or an ''object'' in the database. The surrogate key is ''not'' deri ...
. The only purpose of the POID is to act as the primary key on the table where it is defined and to be referenced as the
foreign key by other tables. Because POIDs, like surrogate keys, do not carry business information, they are immune to changes in the form or meaning of business data.
See also
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Natural key
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Primary key
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Surrogate key
A surrogate key (or synthetic key, pseudokey, entity identifier, factless key, or technical key) in a database is a unique identifier for either an ''entity'' in the modeled world or an ''object'' in the database. The surrogate key is ''not'' deri ...
*
Unique key In relational database management systems, a unique key is a candidate key that is not the primary key of the relation. All the candidate keys of a relation can uniquely identify the records of the relation, but only one of them is used as the prim ...
*
Object identifier
In computing, object identifiers or OIDs are an identifier mechanism standardized by the International Telecommunication Union (ITU) and ISO/IEC for naming any object, concept, or "thing" with a globally unambiguous persistent name.
Syntax and le ...
External links
Persistent Object ID ServiceWhat is a Persistent Object Identifier and why should I care?Persistent Object Database theory