Stand Alone Data Dictionary
This type of database in the DBMS is very adaptive because it grants the administrator in charge of the confidential information complete autonomy to define and manage all crucial data. Whether the information is printed or not has nothing to do with it. A data dictionary that has a stand-alone format enables database designers to have the flexibility to communicate with end users regardless of their data dictionaries format.
There is no standard format for data dictionaries. Here are some common elements:
- Data Elements: The data dictionary describes each data element by specifying the names, data types, storage formats and validation rules.
- Table: All information about the table, such as the user who created the table, the number of rows and columns, the date the table was created and entered, etc.
- Indexes: Indexes for database tables are stored in the data dictionary. The DBMS stores the index name used and index attributes, locations, and properties, as well as the creation date, in each index.
- Programs: Applications defined for database access, reports, application formats and screens, SQL queries, etc. also stored in the data dictionary.
- Relationships between data elements: A data dictionary stores relationship types; for example, if it is mandatory or optional, the nature of the relationship and connection, etc.
- Administration and End Users: The data dictionary stores all administrative and end user data.
Metadata in a DBMS, stored in a data dictionary, is like a monitor that controls database usage and whether users are allowed to access the database.
What is Data Dictionary?
In a database management system (DBMS), a data dictionary can be defined as a component that stores a collection of names, definitions, and attributes for data elements used in the database. The database stores metadata, that is, information about the database. These data elements are then used as part of a database, research project, or information system.
It stores all information about relationships or tables, from the schema and constraints used. All metadata is preserved. In general, metadata refers to information about data. Thus, storing the connection scheme and other metadata in a single structure called a data dictionary or system directory. A data dictionary is like an A-Z dictionary of a relational database system that stores all the information about every relationship in the database.