Blur database
Refers to a database that can handle blurred data. The general database is based on two direct logic and precise data tools, and it is not possible to express many blurred things. With the establishment of the fuzzy mathematics system, people can use the quantity to describe the fuzzy events and can perform a fuzzy operation. This can introduce incomplete, uncertainty, and fuzzy into the database system, thereby forming a fuzzy database. There are two main aspects of fuzzy database research, first of all, how to store fuzzy data in the database; secondly, it is a function that defines various operations to establish fuzzy data. The representation of the fuzzy number is mainly blurred, the number of blurred centers, the number of blurred collections, and the membership function.
Statistical database
Manage statistics database systems. Such databases contain a large amount of data records, but its purpose is to provide users with various statistical summary information instead of providing information of a single record.
Net database
Processing a database of a network data model with a node with a record type. The treatment method is to decompose the mesh structure into several secondary tree structures, called the system. The type type is a description of the connection between two or more record types. In a system type, there is a record type being dominated, called the main record type, and the other is called a member record type. The connection between the main and members is a couple of contacts. The representative of the mesh database is a DBTG system. In 1969, the US Codasyl organization proposed a "DBTG Report", and later, the system implemented according to DBTG reports is generally called the DBTG system. Existing network database systems are mostly using DBTG solutions. The DBTG system is a typical three-level structural system: submodel, mode, storage mode. The corresponding data definition language is called a child mode definition language SSDDL, mode definition language SDDL, and device media control language DMCL. There is also a data manipulation language DML.
Deductive database
Refers to a database with interpretation. In general, it is implemented with a database management system and a rule management system. Store the fact data for reasoning in the database, referred to as an extension database; defined the fact that the logical rules define the facts to be exported, called a connotation database. The main research content is how effective calculation of logical rules reasoning. Specifically: the optimization of recursive queries, consistency maintenance of rules.
