a metadata repository stores metadata instead of actual data in dbms.
a metadata repository stores metadata instead of actual data in dbms.
what stores metadata instead of actual data in dbms?
a metadata repository
metadata repositories should store metadata in four classifications: ownership, descriptive characteristics, rules and policies, and physical characteristics. ownership, showing the data owner and the application owner. the descriptive characteristics, define the names, types and lengths, and definitions describing business data or business processes. rules and policies, will define security, data cleanliness, timelines for data, and relationships. physical characteristics define the origin or source, and physical location. like building a logical data model for creating a database, a logical meta model can help identify the metadata requirements for business data. the metadata repository will be centralized, decentralized, or distributed. a centralized design means that there is one database for the metadata repository that stores metadata for all applications business wide. a centralized metadata repository has the same advantages and disadvantages of a centralized database. easier to manage because all the data is in one database, but the disadvantage is that bottlenecks may occur.
metadata repository
the terms "data dictionary" and "data repository" indicate a more general software utility than a catalogue. a "catalogue" is closely coupled with the dbms software. it provides the information stored in it to the user and the dba, but it is mainly accessed by the various software modules of the dbms itself, such as ddl and dml compilers, the query optimiser, the transaction processor, report generators, and the constraint enforcer. on the other hand, a "data dictionary" is a data structure that stores metadata, i.e., (structured) data about information. the software package for a stand-alone data dictionary or data repository may interact with the software modules of the dbms, but it is mainly used by the designers, users and administrators of a computer system for information resource management. these systems maintain information on system hardware and software configuration, documentation, application and users as well as other information relevant to system administration.
data dictionary