Difference between Active and Passive Data Dictionary
Prerequisite –Short note on Data Dictionary
Data Dictionary is a part of disk storage that is heavily used to store metadata of the structure of the database. For the efficient implementation of these data dictionaries, great importance should be given to developing a good design. The data dictionary can be defined as a collection of information of all data elements or contents of databases such as data types, 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.
There are two types of Data Dictionary i.e, Active Data Dictionary and Passive Data Dictionary, and we have discussed the differences between these two below.
1. Active Data Dictionary :
An active data dictionary is a type of dictionary that is very consistent and managed automatically by the DBMS. In the active data dictionary, when any modification or changes is executed by the DBMS, then this dictionary it also gets modified by the DBMS automatically. Any alteration or modification in the structure of the database can also be seen in the data dictionary with the help of its feature i.e, automatic updating of information by the DBMS. In this dictionary, there is some impact on the structure of the database in the modification process or when we are changing some data in the database.
The benefit of this data dictionary is that it does not need any external maintenance software or tool and also there is no extra cost for the maintenance of the data dictionary as the database management system automatically manages this dictionary.
2. Passive Data Dictionary :
This data dictionary also has the storage for centralizing the metadata. Also, there is no impact on the structure (means the structure can be modified) of the database in the passive data dictionary which was in the case of the active data dictionary. One of the disadvantages of a passive data dictionary is that it does not require any dedicated software for updating or modification. Another disadvantage of this dictionary is that it requires a lot of maintenance cost and also requires other teams to manually maintain the database and if this process is not done or handled correctly then there is a chance that the database and data dictionary gets out of sync. Also, this data dictionary is not a choice for many users as it is not easy to maintain as an active dictionary.
Difference Between Active and Passive Data Dictionary : Active Data Dictionary Passive Data Dictionary
The database management system automatically maintains the active data dictionary. The passive data dictionary is modified whenever the structure of the database is changed. The active data dictionary is very consistent with the structure and the definition of the database. As the process of maintaining or modification is manual, so it is not consistent and not updated with the current structure of the database. Another name of this dictionary is integrated data dictionary. Another name of this dictionary is a non-integrated dictionary or a standalone dictionary. The database management systems automatically manage this dictionary. The users are responsible for manually managing this dictionary. It doesn’t require any separate database. It requires a separate database for working with this dictionary. Mostly, relational database management systems (RDBMS) contain this type of dictionary as it can be easily derived from their system catalog. As the passive data dictionary requires a separate database, so it allows the programmers to remain independent of using a particular RDBMS. It doesn’t provide a good User Interface. It provides you a friendly User Interface. The information in an active data dictionary is up-to-date as it is automatically managed. The information in a passive data dictionary is not up-to-date as it is managed manually by the users.
Active Data Dictionary
Passive Data Dictionary
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