The Data Dictionary helps manage the database It has a numbe

The Data Dictionary helps manage the database. It has a number of views. What do these views allow the DBA to do?

Solution

The phrases statistics dictionary and data repository suggest a extra standard software program software than a list. a catalogue is intently coupled with the DBMS software program. It provides the records saved in it to the user and the DBA, but it\'s miles especially accessed through the numerous software program modules of the DBMS itself, including DDL and DML compilers, the question optimiser, the transaction processor, record mills, and the constraint enforcer. on the other hand, a data dictionary is a information shape that shops metadata, i.e., (based) information approximately facts. The software program package deal for a stand-by myself facts dictionary or facts repository may additionally interact with the software program modules of the DBMS, however it is mainly used by the designers, customers and directors of a laptop machine for data useful resource control. these structures hold information on device hardware and software program configuration, documentation, utility and customers as well as other data relevant to device administration.[2]

If a facts dictionary gadget is used only via the designers, customers, and administrators and not by the DBMS software, it\'s miles referred to as a passive information dictionary. in any other case, it\'s far known as an energetic data dictionary or statistics dictionary. whilst a passive information dictionary is updated, it\'s miles accomplished so manually and independently from any adjustments to a DBMS (database) shape. With an active facts dictionary, the dictionary is up to date first and modifications arise within the DBMS automatically as a result.

Database customers and alertness developers can advantage from an authoritative statistics dictionary record that catalogs the employer, contents, and conventions of one or more databases.[3] This generally consists of the names and descriptions of numerous tables (records or Entities) and their contents (fields) plus extra details, like the sort and duration of every data element. any other essential piece of statistics that a statistics dictionary can provide is the relationship among Tables. that is on occasion cited in Entity-dating diagrams, or if using Set descriptors, figuring out which units database Tables participate in.

In an energetic facts dictionary constraints may be positioned upon the underlying facts. as an instance, a range may be imposed at the fee of numeric statistics in a records detail (field), or a document in a table may be compelled to participate in a hard and fast dating with some other file-type. additionally, a allotted DBMS can also have certain region specifics defined inside its energetic records dictionary (e.g. where Tables are bodily positioned).

The facts dictionary includes report kinds (tables) created inside the database with the aid of structures generated command documents, tailor-made for each supported back-end DBMS. Command documents comprise sq. Statements for CREATE desk, CREATE unique INDEX, modify table (for referential integrity), and many others., the usage of the precise statement required by using that sort of database.