DATABASE DICTIONARY SHORT NOTE

              Data Dictionary

Data dictionary store metadata is heavily used for the structure of the database, so the dictionary should have a good design and efficiency implementation. In the database system, before actually reading or updating data, the metadata file is consulted, the data dictionary is also used to store, DDL is permanently set of tables
 Define DDL Database Plans In an integrat -ed system the data dictionary is for infor -mation related to external conceptual and internal level of the database. It satisfies the source of each data value, its frequency and actual editing related to updates are included. And when to each update
Currently the data dictionary system is available as an add-on in DBMS standards included to integrate data dictionary features with database management system, so that the database has two databases. Metadata and other data can be tampered with using an integrated DDL DML.
1- data definition language -The data dictionary is a m
etadata file because it is consulted before inserting the data and it is read and modified in the database systems data definition language data definition language provided commands for define relations schemas deleting relationship creative index and modify relationship schemas.
2- data manipulation language- Data manipulation means the information storage, database recovery, new information details, modify information, or delete the information stored in the database  data manipulation language is a language that enable user to access of manipulated data as organised by the associated data model