Persistent Object Identifier
Encyclopedia
In database
design, a Persistent Object Identifier (POID) is a unique identifier
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
. 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.
Database
A database is an organized collection of data for one or more purposes, usually in digital form. The data are typically organized to model relevant aspects of reality , in a way that supports processes requiring this information...
design, a Persistent Object Identifier (POID) is a unique identifier
Unique key
In relational database design, a unique key can uniquely identify each row in a table, and is closely related to the Superkey concept. A unique key comprises a single column or a set of columns. No two distinct rows in a table can have the same value in those columns if NULL values are not used...
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
Surrogate key
A surrogate 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 derived from application data.- Definition :There are at least two definitions of a surrogate:...
. 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
Foreign key
In the context of relational databases, a foreign key is a referential constraint between two tables.A foreign key is a field in a relational table that matches a candidate key of another table...
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
- Natural keyNatural keyIn relational model database design, a natural key is a candidate key that has a logical relationship to the attributes within that row. A natural key is sometimes called a domain key.The main advantage of a natural key over a surrogate key, which has no...
- Primary key
- Surrogate keySurrogate keyA surrogate 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 derived from application data.- Definition :There are at least two definitions of a surrogate:...
- Unique keyUnique keyIn relational database design, a unique key can uniquely identify each row in a table, and is closely related to the Superkey concept. A unique key comprises a single column or a set of columns. No two distinct rows in a table can have the same value in those columns if NULL values are not used...
- Object identifierObject identifierIn computing, an object identifier or OID is an identifier used to name an object . Structurally, an OID consists of a node in a hierarchically-assigned namespace, formally defined using the ITU-T's ASN.1 standard. Successive numbers of the nodes, starting at the root of the tree, identify each...