How to document Oracle database?

In Oracle, you would use the COMMENT command to:

[...] add to the data dictionary a comment about a table or table column, view, materialized view, operator, indextype, mining model, or edition.

Most tools (PL/SQL Developer, Toad...) will display these comments in appropriate fields when you browse the database schema.

The comments can be queried directly with the *COMMENTS dictionary views, such as ALL_TAB_COMMENTS.

In Oracle there are table and column comments that can be used for documentation.

These comments can easily be added by the following commands:

COMMENT ON TABLE my_table IS 'Documentation of my table'
/


COMMENT ON COLUMN my_table.my_columns IS 'Documentation of my column'
/