SQL - Data Definition / Data Dictionary Language (DDL)

Data System Architecture


Data definition language (DDL) is a data manipulation statements that manages the data dictionary of a database.

The three principal commands are:

  • ALTER,
  • and DROP

but you can also find:

  • TRUNCATE to remove all records from a table, including all spaces allocated for the records are removed
  • COMMENT to add comments to the data dictionary
  • RENAME to rename an object
  • GRANT privileges on object
  • REVOKE privileges on object
  • FLASHBACK restores an earlier version of a table or database
  • PURGE removes database objects from the recycle bin
  • COMMENT on a particular object

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