Taxonomy - Data Management Services

Data Management Services

Central to most systems is the management of data that can be defined independently of the processes that create or use it, maintained indefinitely, and shared among many processes. Data management services include:

Data dictionary/repository services allow data administrators and information engineers to access and modify data about data (i.e., metadata). Such data may include internal and external formats, integrity and security rules, and location within a distributed system. Data dictionary and repository services also allow end users and applications to define and obtain data that are available in the database. Data administration defines the standardization and registration of individual data element types to meet the requirements for data sharing and interoperability among information systems throughout the enterprise. Data administration functions include procedures, guidelines, and methods for effective data planning, analysis, standards, modeling, configuration management, storage, retrieval, protection, validation and documentation. Data dictionaries are sometimes tied to a single database management system, but heterogeneous data dictionaries will support access to different DBMSs. Repositories can contain a wide variety of information including Management Information Bases or CASE-related information. Object oriented systems may provide repositories for objects and interfaces, described under implementation repository services and interface repository services in the paragraph on Object Services.
Database management system (DBMS) services provide controlled access to structured data. To manage the data, the DBMS provides concurrency control and facilities to combine data from different schemas. Different types of DBMS support different data models, including relational, hierarchical, network, object-oriented and flat-file models. Some DBMSs are designed for special functions such as the storage of large objects or multimedia data. DBMS services are accessible through a programming language interface, an interactive data manipulation language interface such as SQL, or an interactive / fourth-generation language interface. Look-up and retrieval services for objects are described separately under query services in the paragraph on Object Services. For efficiency, database management systems often provide specific services to create, populate, move, backup, restore, recover and archive databases, although some of these services could be provided by the general file management capabilities described in the section on Operating System Services or a specific backup service. Some database management systems support distribution of the database, including facilities for remotely updating records, data replication, locating and caching data, and remote management.
Object Oriented Database Management System services provide storage for objects and interfaces to those objects. These services may support the implementation repository, interface repository and persistent object services in the paragraph on Object Services.
File management services provide data management through file access methods including indexed sequential (ISAM) and hashed random access. Flat file and directory services are described in the Operating System Services category.

The following functional areas are currently supported mainly by applications, but are progressing towards migration into the Application Platform:

Query processing functions that provide for interactive selection, extraction, and formatting of stored information from files and databases. Query processing functions are invoked via user-oriented languages and tools (often referred to as fourth generation languages), which simplify the definition of searching criteria and aid in creating effective presentation of the retrieved information (including use of graphics).
Screen generation functions that provide the capability to define and generate screens that support the retrieval, presentation, and update of data.
Report generation functions that provide the capability to define and generate hard copy reports composed of data extracted from a database.
Networking/concurrent access functions that manage concurrent user access to Database Management System (DBMS) functions.
Warehousing functions provide the capability to store very large amounts of data, usually captured from other database systems and to perform on-line analytical processing on it in support of ad-hoc queries.