Types of Data Dictionary
Data Dictionary is basically of two types. We will discuss each of them.
- Integrated Data Dictionary
- Stand Alone Data Dictionary
1. Integrated Data Dictionary
Integrated Data Dictionary can be seen as a catalog that can be maintained by the relational database. In previous databases, there is not any functionality of Integrated Data Dictionary, so they use Stand Alone Data Dictionary.
There are two types of Integrated Data Dictionary.
- Active Data Dictionary: Active Database Dictionary is a type of database that is updated automatically in case any changes are to be done to the database. These are self-updating.
- Passive Data Dictionary: Passive Databases are the databases that have to be maintained or updated manually in case of any changes have been made to the system.
2. Stand Alone Data Dictionary
Stand Alone Data Dictionary is a type of flexible data dictionary as Database Administrator has ease of managing data. It does not require data that is computer-based. It has no fixed format. But some elements are common in this kind of database.
- Data Elements: It has the elements like name, datatype, validation rules, etc.
- Tables: These contain all the necessary information that is required for the table, how many rows in the table, how many columns in the table, etc.
- Index: The index of the databases is to be stored here.
- Programs: These are used for accessing the database, and can include SQL Queries, Reports, etc.
- Relationship between Data Elements: This stores the relationship among the different databases, like cardinality, connectivity, etc.
Short Note on Data Dictionary
A Data Dictionary comprises two words i.e. Data which simply means information being collected through some sources and Dictionary means where this information is available.
A Data Dictionary can be defined as a collection of information on all data elements or contents of databases such as data types, and text descriptions of the system. It makes it easier for users and analysts to use data as well as understand and have common knowledge about inputs, outputs, components of a database, and intermediate calculations.