altinity-expert-clickhouse-grants

Diagnostics

Run all queries from the file checks.sql and analyze the results.

Propose Minimal Grants

Provide the smallest set of GRANT statements that match observed needed_grant values. Prefer role-based grants when the user already uses roles.

Example pattern:

-- Direct grants
GRANT SELECT ON system.processes TO user_x;
GRANT SELECT ON INFORMATION_SCHEMA.COLUMNS TO svc_y;
GRANT CLUSTER ON *.* TO svc_z;

-- Role-based grants (preferred)
GRANT SELECT ON system.processes TO role_analytics;
GRANT role_analytics TO user_x;

Post-Upgrade Compatibility Checks

Verify access_control_improvements settings, which can change privilege requirements:

• select_from_system_db_requires_grant
• select_from_information_schema_requires_grant
• on_cluster_queries_require_cluster_grant

If these are enabled post-upgrade, users may require new explicit grants for system.*, INFORMATION_SCHEMA.*, or CLUSTER.