docs/en/sql-reference/sys/sys.md
This topic describes how to view the exclusive metadata of your StarRocks cluster via system-defined views.
Each StarRocks cluster maintains a database sys, which contains several read-only, system-defined views. These metadata views provide a unified, easy-to-use interface that allows you to have an overall insight into the privilege structure, object dependencies, and other information within your StarRocks cluster.
sysYou can view the exclusive metadata information within a StarRocks instance by querying the content of views in sys.
The following example checks the privileges granted to user-defined roles by querying the view grants_to_roles.
MySQL > SELECT * FROM sys.grants_to_roles LIMIT 5\G
*************************** 1. row ***************************
GRANTEE: role_test
OBJECT_CATALOG: default_catalog
OBJECT_DATABASE: db_test
OBJECT_NAME: tbl1
OBJECT_TYPE: TABLE
PRIVILEGE_TYPE: SELECT, ALTER
IS_GRANTABLE: NO
*************************** 2. row ***************************
GRANTEE: role_test
OBJECT_CATALOG: default_catalog
OBJECT_DATABASE: db_test
OBJECT_NAME: tbl2
OBJECT_TYPE: TABLE
PRIVILEGE_TYPE: SELECT
IS_GRANTABLE: YES
*************************** 3. row ***************************
GRANTEE: role_test
OBJECT_CATALOG: default_catalog
OBJECT_DATABASE: db_test
OBJECT_NAME: mv_test
OBJECT_TYPE: MATERIALIZED VIEW
PRIVILEGE_TYPE: SELECT
IS_GRANTABLE: YES
*************************** 4. row ***************************
GRANTEE: role_test
OBJECT_CATALOG: NULL
OBJECT_DATABASE: NULL
OBJECT_NAME: NULL
OBJECT_TYPE: SYSTEM
PRIVILEGE_TYPE: CREATE RESOURCE GROUP
IS_GRANTABLE: NO
syssys contains the following metadata views:
| View | Description |
|---|---|
| grants_to_roles | Records the information of privileges that are granted to user-defined roles. |
| grants_to_users | Records the information of privileges that are granted to users. |
| role_edges | Records the grantees of roles. |
| object_dependencies | Records the dependency relationship of asynchronous materialized views. |
| policy_references | Records the objects row access policies and column masking policies reference. |
| fe_locks | Records the information about metadata locks in StarRocks FE. |
:::note
As per their scenarios of applications, views in sys are only accessible to some admin roles by default. Depending on your specific needs, you can grant other users the SELECT privilege on these views.
:::