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In an object database (also object oriented database), information is represented in the form of objects as used in object-oriented programming. When database capabilities are combined with object programming language capabilities, the result is an object database management system (ODBMS). An ODBMS makes database objects appear as programming language objects in one or more object programming languages. An ODBMS extends the programming language with transparently persistent data, concurrency control, data recovery, associative queries, and other capabilities. In strictly mathematical branches of computer science the term object is used in a purely mathematical sense to refer to any thing. While this interpretation is useful in the discussion of abstract theory, it is not concrete enough to serve as a primitive datatype in the discussion of more concrete... Object-oriented programming (OOP) is a programming paradigm that uses objects and their interactions to design applications and computer programs. ...

Some object-oriented databases are designed to work well with object-oriented programming languages such as Python, Java, C#, Visual Basic .NET, C++ and Smalltalk. Others have their own programming languages. ODBMSs use exactly the same model as object-oriented programming languages. Python is a general-purpose, high-level programming language. ... Java language redirects here. ... The title given to this article is incorrect due to technical limitations. ... Visual Basic . ... C++ (pronounced ) is a general-purpose programming language. ... For other uses, see Small talk. ...

Object databases are generally recommended when there is a business need for high performance processing on complex data.

History

Object Database management systems grew out of research during the early to mid-1970s into having intrinsic database management support for graph-structured objects. The term "object-oriented database system" first appeared around 1985^{[citation needed]}. Notable research projects included Encore-Ob/Server (Brown University), EXODUS (University of Wisconsin), IRIS (Hewlett-Packard), ODE (Bell Labs), ORION (Microelectronics and Computer Technology Corporation or MCC), Vodak (GMD-IPSI), and Zeitgeist (Texas Instruments). The ORION project had more published papers than any of the other efforts. Won Kim of MCC compiled the best of those papers in a book published by The MIT Press.^[1] The 1970s decade refers to the years from 1970 to 1979, also called The Seventies. ... This article is about the year. ... Brown University is a private university located in Providence, Rhode Island. ... University of Wisconsin redirects here. ... Bell Laboratories (also known as Bell Labs and formerly known as AT&T Bell Laboratories and Bell Telephone Laboratories) was the main research and development arm of the United States Bell System. ... The MCC headquarters building in Austin, Texas Microelectronics and Computer Technology Corporation (MCC) was the first, and is now one of the largest, United States computer industry research and development consortia. ...

Early commercial products included Gemstone (Servio Logic, name changed to GemStone Systems), Gbase (Graphael), and Vbase (Ontologic). The early to mid-1990s saw additional commercial products enter the market. These included ITASCA (Itasca Systems), Jasmine (Fujitsu, marketed by Computer Associates), Matisse (Matisse Software), Objectivity/DB (Objectivity, Inc.), ObjectStore (Progress Software, acquired from eXcelon which was originally Object Design), ONTOS (Ontos, Inc., name changed from Ontologic), O₂^[2] (O₂ Technology, merged with several companies, acquired by Informix, which was in turn acquired by IBM), POET (now FastObjects from Versant which acquired Poet Software), and Versant Object Database (Versant Corporation). Some of these products remain on the market and have been joined by new open source and commercial products such as InterSystems CACHÉ (see the product listings below). Gemstone is a proprietary application framework that was first available for Smalltalk as an object database. ... Objectivity/DB is a commercial object oriented database management system ODBMS produced by Objectivity, Inc. ... ObjectStore is a commercial object database, which is a specialized type of database designed to handle data created by applications that use object-oriented programming techniques. ... Progress Software Corporation (Nasdaq: PRGS) is an American software company which sells business application infrastructure software. ... For other uses, see IBM (disambiguation) and Big Blue. ... InterSystems Corporation is a vendor of database products, and one of the original vendors of MUMPS programming platforms. ...

Object database management systems added the concept of persistence to object programming languages. The early commercial products were integrated with various languages: GemStone (Smalltalk), Gbase (LISP), and Vbase (COP). For much of the 1990s, C++ dominated the commercial object database management market. Vendors added Java in the late 1990s and more recently, C#. It has been suggested that Orthogonal persistence be merged into this article or section. ... For other uses, see Small talk. ... Lisp is a family of computer programming languages with a long history and a distinctive fully-parenthesized syntax. ... The C Object Processor (COP) was a superset of the C programming language. ... C++ (pronounced ) is a general-purpose programming language. ... Java is an object-oriented programming language developed by James Gosling and colleagues at Sun Microsystems in the early 1990s. ... The title given to this article is incorrect due to technical limitations. ...

Starting in 2004, object databases have seen a second growth period when open source object databases emerged that were widely affordable and easy to use, because they are entirely written in OOP languages like Java or C#, such as db4o (db4objects) and Perst (McObject). Recently another open source object database Magma has been in development. Magma is written in Squeak. Commercial products such as InterSystems CACHÉ also appear to be gaining acceptance. Year 2004 (MMIV) was a leap year starting on Thursday of the Gregorian calendar. ... Open source refers to projects that are open to the public and which draw on other projects that are freely available to the general public. ... There are very few or no other articles that link to this one. ... Perst is an open source, dual license, object-oriented embedded database management system (ODBMS), available in two implementations: one that is developed entirely in the Java programming language, and another developed in the C# language (for applications that will run within the Microsoft . ... Screenshot of the Squeak VM running under X11 on Kubuntu Linux. ... InterSystems Corporation is a vendor of database products, and one of the original vendors of MUMPS programming platforms. ...

Adoption of object databases

Object databases based on persistent programming acquired a niche in application areas such as engineering and spatial databases, telecommunications, and scientific areas such as high energy physics and molecular biology. They have made little impact on mainstream commercial data processing, though there is some usage in specialized areas of financial services^{[citation needed]}. It is also worth noting that object databases held the record for the World's largest database (being first to hold over 1000 Terabytes at Stanford Linear Accelerator Center "Lessons Learned From Managing A Petabyte") and the highest ingest rate ever recorded for a commercial database at over one Terabyte per hour. Telecommunication involves the transmission of signals over a distance for the purpose of communication. ... Particle physics is a branch of physics that studies the elementary constituents of matter and radiation, and the interactions between them. ... Molecular biology is the study of biology at a molecular level. ... Financial services is a term used to refer to the services provided by the finance industry. ...

Another group of object databases focuses on embedded use in devices, packaged software, and realtime systems.

Technical features

Most object databases also offer some kind of query language, allowing objects to be found by a more declarative programming approach. It is in the area of object query languages, and the integration of the query and navigational interfaces, that the biggest differences between products are found. An attempt at standardization was made by the ODMG with the Object Query Language, OQL. Query languages are computer languages used to make queries into databases and information systems. ... Declarative programming is a term with two distinct meanings, both of which are in current use. ... The Object Data Management Group (ODMG) was set up around 1993 to develop a new DBMS (database management system) standard that would bring the (putative) advantages of an object oriented programming methodology to the power of database technology, as it was at the time. ... Object Query Language (OQL) is a query language standard for object-oriented databases modelled after SQL. OQL was developed by the Object Data Management Group (ODMG). ...

Access to data can be faster because joins are often not needed (as in a tabular implementation of a relational database). This is because an object can be retrieved directly without a search, by following pointers. (It could, however, be argued that "joining" is a higher-level abstraction of pointer following.) A JOIN clause in SQL combines records from two tables in a relational database and results in a new (temporary) table, also called a joined table. Structured Query Language (SQL:2003) specifies two types of joins: inner and outer. ... A relational database is a database that conforms to the relational model, and refers to a databases data and schema (the databases structure of how those data are arranged). ...

Another area of variation between products is in the way that the schema of a database is defined. A general characteristic, however, is that the programming language and the database schema use the same type definitions.

Multimedia applications are facilitated because the class methods associated with the data are responsible for its correct interpretation.

Many object databases offer support for versioning. An object can be viewed as the set of all its versions. Also, object versions can be treated as objects in their own right. Some object databases also provide systematic support for triggers and constraints which are the basis of active databases. Revision control is an aspect of documentation control wherein changes to documents are identified by incrementing an associated number or letter code, termed the revision level, or simply revision. It has been a standard practice in the maintenance of engineering drawings for as long as the generation of such drawings... A database trigger is procedural code that is automatically executed in response to certain events on a particular table in a database. ... An active database is a database that includes active rules, mostly in the form of ECA rules. ...

Advantages and disadvantages

Benchmarks between ODBMSs and RDBMSs have shown that ODBMS can be clearly superior for certain kinds of tasks. The main reason for this is that many operations are performed using navigational rather than declarative interfaces, and navigational access to data is usually implemented very efficiently by following pointers.^[3] A relational database management system (RDBMS) is a database management system (DBMS) that is based on the relational model as introduced by Edgar F. Codd. ... Navigational databases incorporate both the network model and hierarchical model of database interfaces. ... In computer science, a declaration specifies a variables dimensions, identifier, type, and other aspects. ...

Critics of navigational database-based technologies like ODBMS suggest that pointer-based techniques are optimized for very specific "search routes" or viewpoints. However, for general-purpose queries on the same information, pointer-based techniques will tend to be slower and more difficult to formulate than relational. Thus, navigation appears to simplify specific known uses at the expense of general, unforeseen, and varied future uses.^{[citation needed]} Navigational databases incorporate both the network model and hierarchical model of database interfaces. ...

Other things that work against ODBMS seem to be the lack of interoperability with a great number of tools/features that are taken for granted in the SQL world including but not limited to industry standard connectivity, reporting tools, OLAP tools, and backup and recovery standards. Additionally, object databases lack a formal mathematical foundation, unlike the relational model, and this in turn leads to weaknesses in their query support. However, this objection is offset by the fact that some ODBMSs fully support SQL in addition to navigational access, e.g. Objectivity/SQL++, Matisse, and InterSystems CACHÉ. Effective use may require compromises to keep both paradigms in sync. Interoperability is a property referring to the ability of diverse systems and organizations to work together (inter-operate). ... Connectivity is the property of a device such as a PC, peripheral, PDA, mobile phone, robot, home appliance, or car that enables it to be connected, generally to a PC or another device without the need of a PC - autonomously. ... Online Analytical Processing, or OLAP (IPA: ), is an approach to quickly provide answers to analytical queries that are multidimensional in nature. ... For other uses of Backup, see Backup (disambiguation). ... Recovery is the first e-book and seventh installment of The New Jedi Order series set in the Star Wars galaxy. ... The relational model for database management is a database model based on predicate logic and set theory. ... InterSystems Corporation is a vendor of database products, and one of the original vendors of MUMPS programming platforms. ...

In fact there is an intrinsic tension between the notion of encapsulation, which hides data and makes it available only through a published set of interface methods, and the assumption underlying much database technology, which is that data should be accessible to queries based on data content rather than predefined access paths. Database-centric thinking tends to view the world through a declarative and attribute-driven viewpoint, while OOP tends to view the world through a behavioral viewpoint. This is one of the many impedance mismatch issues surrounding OOP and databases. Encapsulation may refer to: information hiding and separation of concerns, in software engineering, the process of enclosing programming elements inside larger, more abstract entities integrated circuit encapsulation, in electronics the design and manufacture of protective packages micro-encapsulation, means to confine material molecular encapsulation, means to confine molecules encapsulation (pharmacology... This article does not cite any references or sources. ...

Although some commentators have written off object database technology as a failure, the essential arguments in its favor remain valid, and attempts to integrate database functionality more closely into object programming languages continue in both the research and the industrial communities.^{[citation needed]}

Standards

The Object Data Management Group (ODMG) was a consortium of object database and object-relational mapping vendors, members of the academic community, and interested parties. Its goal was to create a set of specifications that would allow for portable applications that store objects in database management systems. It published several versions of its specification. The last release was ODMG 3.0. By 2001, most of the major object database and object-relational mapping vendors claimed conformance to the ODMG Java Language Binding. Compliance to the other components of the specification was mixed.^[4] In 2001, the ODMG Java Language Binding was submitted to the Java Community Process as a basis for the Java Data Objects specification. The ODMG member companies then decided to concentrate their efforts on the Java Data Objects specification. As a result, the ODMG disbanded in 2001. The Object Data Management Group (ODMG) was conceived in the summer of 1991 at a breakfast with object database vendors that was organized by Rick Cattell of Sun Microsystems. ... The Java Community Process or JCP, established in 1995, is a formalized process which allows interested parties to be involved in the definition of future versions and features of the Java platform. ... Java Data Objects (JDO) is a specification of Java object persistence. ...

Many object database ideas were also absorbed into SQL:1999 and have been implemented in varying degrees in object-relational database products. SQL (IPA: or ) is a computer language designed for the retrieval and management of data in relational database management systems, database schema creation and modification, and database object access control management. ... An object-relational database (ORD) or object-relational database management system (ORDBMS) provides a relational database management system that allows developers to integrate a database with their own custom data-types and methods. ...

In 2005 Cook, Rai, and Rosenberger proposed to drop all standardization efforts to introduce additional object-oriented query APIs but rather use the OO programming language itself, i.e., Java and .NET, to express queries. As a result, Native Queries emerged. Similarly, Microsoft announced Language Integrated Query (LINQ) and DLINQ, an implementation of LINQ, in September 2005, to provide close, language-integrated database query capabilities with its programming languages C# and VB.NET 9. Native Queries are a concise and type-safe way to express queries directly as Java and C# methods. ... Language intergrated query (LINQ) is a Microsoft project that aims to add a native querying syntax to C# and VB.Net. ...

In February 2006, the Object Management Group (OMG) announced that they had been granted the right to develop new specifications based on the ODMG 3.0 specification and the formation of the Object Database Technology Working Group (ODBT WG). The ODBT WG plans to create a set of standards that incorporates advances in object database technology (e.g., replication), data management (e.g., spatial indexing), and data formats (e.g., XML) and to include new features into these standards that support domains where object databases are being adopted (e.g., real-time systems). Object Management Group (OMG) is a consortium, originally aimed at setting standards for distributed object-oriented systems, and is now focused on modeling (programs, systems and business processes) and model-based standards in some 20 vertical markets. ...

References and notes

1. ^ Kim, Won. Introduction to Object-Oriented Databases. The MIT Press, 1990. ISBN 0-262-11124-1
2. ^ Bancilhon, Francois; Delobel,Claude; and Kanellakis, Paris. Building an Object-Oriented Database System: The Story of O₂. Morgan Kaufmann Publishers, 1992. ISBN 1-55860-169-4.
3. ^ Animation showing how an object database works
4. ^ Barry, Douglas and Duhl, Joshua. Object Storage Fact Books: Object DBMSs and Object-Relational Mapping. Barry & Associates, Inc., 2001. Pages showing the ODMG compliance for both object database and object-relational mapping products in 2001.

See also

• Comparison of object database management systems
• Zope Object Database
• Enterprise Objects Framework
• Object Data Management Group
• Object-relational mapping
• Persistence
• Relational model
• Object-relational impedance mismatch
• The Third Manifesto

Information about what fundamental ODBMS features are implemented natively. ... // The Zope Object Database (ZODB) transparently persists Python objects in a transactional database. ... The Enterprise Objects Framework (or more commonly, EOF) was introduced by NeXT in 1994 as a pioneering object-relational mapping product for its NeXTSTEP and OpenStep development platforms. ... The Object Data Management Group (ODMG) was conceived in the summer of 1991 at a breakfast with object database vendors that was organized by Rick Cattell of Sun Microsystems. ... Object-Relational mapping (aka O/RM, ORM, and O/R mapping) is a programming technique for converting data between incompatible type systems in databases and object-oriented programming languages. ... Persistence is the term used in computer science to describe a capability used by a computer programmer to store data structures in non-volatile storage such as a file system or a relational database. ... The relational model for database management is a database model based on predicate logic and set theory. ... This article does not cite any references or sources. ... The Third Manifesto (1995) is Christopher J. Dates and Hugh Darwens proposal for future relational database management systems that would avoid Object-Relational Impedance Mismatch between object-oriented programming languages and RDBMSs by fully supporting all the capabilities of the relational model. ... A database management system (DBMS) is computer software designed for the purpose of managing databases based on a variety of data models. ... A data model is not just a way of structuring data: it also defines a set of operations that can be performed on the data. ... Database normalization, sometimes referred to as canonical synthesis, is a technique for designing relational database tables to minimize duplication of information and, in so doing, to safeguard the database against certain types of logical or structural problems, namely data anomalies. ... Database tables/indexes are typically stored in memory or on hard disk in one of many forms, ordered/unordered Flat files, ISAM, Heaps, Hash buckets or B+ Trees. ... According to Elmasri and Navathe (2004, p. ... An example of a database that has not enforced referential integrity. ... Relational algebra, an offshoot of first-order logic, is a set of relations closed under operators. ... The relational calculus refers to the two calculi, the tuple calculus and the domain calculus, that are part of the relational model for databases and that provide a declarative way to specify database queries. ... A relational database is a database that conforms to the relational model, and refers to a databases data and schema (the databases structure of how those data are arranged). ... A relational database management system (RDBMS) is a database management system (DBMS) that is based on the relational model as introduced by E. F. Codd. ... The relational model for database management is a database model based on predicate logic and set theory. ... An object-relational database (ORD) or object-relational database management system (ORDBMS) provides a relational database management system that allows developers to integrate a database with their own custom data-types and methods. ... In computer science, transaction processing is information processing that is divided into individual, indivisible operations, called Each transaction must succeed or fail as a complete unit; it cannot remain in an intermediate state. ... This article is about computing. ... For other uses, see acid (disambiguation). ... The Greek lowercase omega (ω) character is historically used by academics to represent Null in relational databases. ... In the relational model a candidate key of a relation variable (relvar) is a set of attributes of that relvar such that (1) at all times it holds in the relation assigned to that variable that there are no two distinct tuples with the same values for these attributes and... In the context of relational databases, a foreign key is a referential constraint between two tables[1]. The foreign key identifies a column or a set of columns in one (referencing) table that refers to a column or set of columns in another (referenced) table. ... In database design, a primary key is a value that can be used to identify a unique row in a table. ... A superkey is defined in the relational model as a set of attributes of a relation variable (relvar) for which it holds that in all relations assigned to that variable there are no two distinct tuples (rows) that have the same values for the attributes in this set. ... A surrogate key is a unique primary key generated by the relational database management system that is not derived from any data in the database and whose only significance is to act as the primary key. ... A database trigger is procedural code that is automatically executed in response to certain events on a particular table in a database. ... In database theory, a view is a virtual or logical table composed of the result set of a query. ... In relational databases, SQL databases, and flat file databases, a table is a set of data elements (values) that is organized using a model of horizontal rows and vertical columns. ... In database packages, the term cursor refers to a control structure for the successive traversal (and potential processing) of records in a result set as returned by a query. ... In in the field of databases in computer science, a transaction log (also database log or binary log) is a history of actions executed by a database management system to guarantee ACID properties over crashes or hardware failures. ... A database transaction is a unit of interaction with a database management system or similar system that is treated in a coherent and reliable way independent of other transactions. ... A database index is a data structure that improves the speed of operations in a table. ... A stored procedure is a subroutine available to applications accessing a relational database system. ... A partition is a division of a logical database or its constituting elements into distinct independent parts. ... SQL (IPA: or ) is a computer language designed for the retrieval and management of data in relational database management systems, database schema creation and modification, and database object access control management. ... An SQL SELECT statement returns a result set of records from one or more tables. ... A SQL INSERT statement adds one or more records to a table in a relational database. ... An UPDATE statement in SQL changes data in one or more records in a relational database management system. ... Wikipedia does not have an article with this exact name. ... An SQL DELETE statement removes one or more records from a table. ... A JOIN clause in SQL combines records from two tables in a relational database and results in a new (temporary) table, also called a joined table. Structured Query Language (SQL:2003) specifies two types of joins: inner and outer. ... In SQL the UNION operator combines the results of two SQL queries into a single table of all matching rows. ... A CREATE statement in SQL creates an object inside of a relational database management system (RDBMS). ... A DROP statement in SQL removes an object from a relational database management system (RDBMS). ... It has been suggested that this article or section be merged into Database transaction. ... A COMMIT statement in SQL ends a transaction within a relational database management system (RDBMS) and makes all changes visible to other users. ... In database technologies, a rollback is an operation which returns the database to some previous state. ... The Truncate statement removes all the data from a table. ... An ALTER statement in SQL changes the properties of an object inside of a relational database management system (RDBMS). ... A relational database is a database that conforms to the relational model, and refers to a databases data and schema (the databases structure of how those data are arranged). ... A simple diagram depicting conversion of a CSV-format flat file database table into a relational database table. ... A deductive database system is a database system which can make deductions (ie: infer additional rules or facts) based on rules and facts stored in the (deductive) database. ... A dimensional database is one which, rather than representing data in multiple relations (as a relational database does), represents key data entities as different dimensions. ... In a hierarchical data model, data are organized into a tree-like structure. ... The network model is a database model conceived as a flexible way of representing objects and their relationships. ... An object-relational database (ORD) or object-relational database management system (ORDBMS) provides a relational database management system that allows developers to integrate a database with their own custom data-types and methods. ... A temporal database is a database management system with built-in time aspects, e. ... An XML database is a data persistence software system that allows data to be imported, accessed and exported in the XML format. ... In computer science -- more specifically, in the field of databases -- concurrency control is a method used to ensure that database transactions are executed in a safe manner (i. ... A data dictionary is a set of metadata that contains definitions and representations of data elements. ... JDBC is an API for the Java programming language that defines how a client may access a database. ... In computing, Open Database Connectivity (ODBC) provides a standard software API method for using database management systems (DBMS). ... Query languages are computer languages used to make queries into databases and information systems. ... The query optimizer is a component of database management system that is used to analyzes queries submitted to database server for execution, and then determines the optimal way to execute the query. ... A query plan (or query execution plan) is an set of steps used to access information in a SQL relational database management system. ... The following is a list of object-oriented database management systems. ... This article or section is not written in the formal tone expected of an encyclopedia article. ... See DBMS for a shorter list of “typical”, representative database management systems. ... The following tables compare general and technical information for a number of relational database management systems. ...

External links

• Object DBMS resource portal
• Benchmark for Databases (open source)