datahub/metadata-ingestion/docs/sources/oracle/oracle_pre.md

Prerequisites

Data Dictionary Mode/Views

The Oracle ingestion source supports two modes for extracting metadata information (see data_dictionary_mode option): ALL and DBA. In the ALL mode, the SQLAlchemy backend queries ALL_ data dictionary views to extract metadata information. In the DBA mode, the Oracle ingestion source directly queries DBA_ data dictionary views to extract metadata information. ALL_ views only provide information accessible to the user used for ingestion while DBA_ views provide information for the entire database (that is, all schema objects in the database).

The following table contains a brief description of what each data dictionary view is used for:

Data Dictionary View	What's it used for?
ALL_TABLES or DBA_TABLES	Get list of all relational tables in the database
ALL_VIEWS or DBA_VIEWS	Get list of all views in the database
ALL_TAB_COMMENTS or DBA_TAB_COMMENTS	Get comments on tables and views
ALL_TAB_COLS or DBA_TAB_COLS	Get description of the columns of tables and views
ALL_COL_COMMENTS or DBA_COL_COMMENTS	Get comments on the columns of tables and views
ALL_TAB_IDENTITY_COLS or DBA_TAB_IDENTITY_COLS	Get table identity columns
ALL_CONSTRAINTS or DBA_CONSTRAINTS	Get constraint definitions on tables
ALL_CONS_COLUMNS or DBA_CONS_COLUMNS	Get list of columns that are specified in constraints
ALL_USERS or DBA_USERS	Get all schema names
ALL_OBJECTS or DBA_OBJECTS	Get stored procedures, functions, and packages
ALL_SOURCE or DBA_SOURCE	Get source code for stored procedures and functions
ALL_ARGUMENTS or DBA_ARGUMENTS	Get arguments for stored procedures and functions
ALL_DEPENDENCIES or DBA_DEPENDENCIES	Get dependency information for database objects
ALL_MVIEWS or DBA_MVIEWS	Get materialized views and their definitions

Data Dictionary Views accessible information and required privileges

• ALL_ views display all the information accessible to the user used for ingestion, including information from the user's schema as well as information from objects in other schemas, if the user has access to those objects by way of grants of privileges or roles.
• DBA_ views display all relevant information in the entire database. They can be queried only by users with the SYSDBA system privilege or SELECT ANY DICTIONARY privilege, or SELECT_CATALOG_ROLE role, or by users with direct privileges granted to them.

Required Permissions

The following permissions are required based on features used:

Basic Metadata (Tables & Views)

-- Using data_dictionary_mode: ALL (default)
GRANT SELECT ON ALL_TABLES TO datahub_user;
GRANT SELECT ON ALL_TAB_COLS TO datahub_user;
GRANT SELECT ON ALL_TAB_COMMENTS TO datahub_user;
GRANT SELECT ON ALL_COL_COMMENTS TO datahub_user;
GRANT SELECT ON ALL_VIEWS TO datahub_user;
GRANT SELECT ON ALL_CONSTRAINTS TO datahub_user;
GRANT SELECT ON ALL_CONS_COLUMNS TO datahub_user;

-- Using data_dictionary_mode: DBA (elevated permissions)
GRANT SELECT ON DBA_TABLES TO datahub_user;
GRANT SELECT ON DBA_TAB_COLS TO datahub_user;
GRANT SELECT ON DBA_TAB_COMMENTS TO datahub_user;
GRANT SELECT ON DBA_COL_COMMENTS TO datahub_user;
GRANT SELECT ON DBA_VIEWS TO datahub_user;
GRANT SELECT ON DBA_CONSTRAINTS TO datahub_user;
GRANT SELECT ON DBA_CONS_COLUMNS TO datahub_user;

Stored Procedures (enabled by default)

-- For ALL mode
GRANT SELECT ON ALL_OBJECTS TO datahub_user;
GRANT SELECT ON ALL_SOURCE TO datahub_user;
GRANT SELECT ON ALL_ARGUMENTS TO datahub_user;
GRANT SELECT ON ALL_DEPENDENCIES TO datahub_user;

-- For DBA mode
GRANT SELECT ON DBA_OBJECTS TO datahub_user;
GRANT SELECT ON DBA_SOURCE TO datahub_user;
GRANT SELECT ON DBA_ARGUMENTS TO datahub_user;
GRANT SELECT ON DBA_DEPENDENCIES TO datahub_user;

Materialized Views (enabled by default)

-- For ALL mode
GRANT SELECT ON ALL_MVIEWS TO datahub_user;

-- For DBA mode
GRANT SELECT ON DBA_MVIEWS TO datahub_user;

Database Name Resolution

GRANT SELECT ON V_$DATABASE TO datahub_user;