Goal Be precise and do not give impossible privileges.
Type Problem detection (Each row in the result could represent a flaw in the design)
Reliability Medium (Medium number of false-positive results)
License MIT License
Fixing Suggestion Revoke the unnecessary privileges.
Data Source INFORMATION_SCHEMA+system catalog
SQL Query
WITH non_updatable_view AS (SELECT table_schema AS view_schema, table_name AS view_name, is_updatable, is_insertable_into
FROM Information_schema.views
WHERE (is_insertable_into='NO' AND is_updatable='NO') 
AND table_schema NOT IN (SELECT schema_name
FROM INFORMATION_SCHEMA.schemata
WHERE schema_name<>'public' AND
schema_owner='postgres' AND schema_name IS NOT NULL)),
modify_priv AS (SELECT tp.grantee, tp.table_schema AS view_schema, tp.table_name AS view_name, array_agg(tp.privilege_type::TEXT) AS privileges
FROM information_schema.table_privileges AS tp INNER JOIN information_schema.tables AS t
ON t.table_schema=tp.table_schema AND t.table_name=tp.table_name
WHERE t.table_type='VIEW' AND tp.table_schema NOT IN  (SELECT schema_name
FROM INFORMATION_SCHEMA.schemata
WHERE schema_name<>'public' AND
schema_owner='postgres' AND schema_name IS NOT NULL)
AND tp.privilege_type IN ('INSERT','UPDATE','DELETE') 
AND grantee <> ALL (SELECT viewowner
FROM pg_catalog.pg_views AS pv
WHERE pv.schemaname=tp.table_schema AND pv.viewname=tp.table_name)
GROUP BY tp.grantee, tp.table_schema, tp.table_name)
SELECT view_schema, view_name, is_updatable, is_insertable_into, grantee, privileges
FROM non_updatable_view INNER JOIN modify_priv USING (view_schema, view_name)
ORDER BY grantee, view_schema, view_name;

SQL statements that help generate fixes for the identified problem.

SQL Query to Generate FixDescription
WITH non_updatable_view AS (SELECT table_schema AS view_schema, table_name AS view_name, is_updatable, is_insertable_into
FROM Information_schema.views
WHERE (is_insertable_into='NO' AND is_updatable='NO') 
AND table_schema NOT IN (SELECT schema_name
FROM INFORMATION_SCHEMA.schemata
WHERE schema_name<>'public' AND
schema_owner='postgres' AND schema_name IS NOT NULL)),
modify_priv AS (SELECT tp.grantee, tp.table_schema AS view_schema, tp.table_name AS view_name, tp.privilege_type AS privilege
FROM information_schema.table_privileges AS tp INNER JOIN information_schema.tables AS t
ON t.table_schema=tp.table_schema AND t.table_name=tp.table_name
WHERE t.table_type='VIEW' AND tp.table_schema NOT IN  (SELECT schema_name
FROM INFORMATION_SCHEMA.schemata
WHERE schema_name<>'public' AND
schema_owner='postgres' AND schema_name IS NOT NULL)
AND tp.privilege_type IN ('INSERT','UPDATE','DELETE') 
AND grantee <> ALL (SELECT viewowner
FROM pg_catalog.pg_views AS pv
WHERE pv.schemaname=tp.table_schema AND pv.viewname=tp.table_name)),
unnecessary_privileges AS (SELECT view_schema, view_name, is_updatable, is_insertable_into, grantee, privilege
FROM non_updatable_view INNER JOIN modify_priv USING (view_schema, view_name))
SELECT format('REVOKE %1$s ON %2$I.%3$I FROM %4$I;', privilege, view_schema, view_name, grantee) AS statements
FROM unnecessary_privileges
ORDER BY grantee, view_schema, view_name;
Revoke the unnecessary privileges.
Collections

This query belongs to the following collections:

NameDescription
Find problems automaticallyQueries, that results point to problems in the database. Each query in the collection produces an initial assessment. However, a human reviewer has the final say as to whether there is a problem or not .
Categories

This query is classified under the following categories:

NameDescription
Derived tablesQueries of this category provide information about the derived tables (views, materialized views), which are used to implement virtual data layer.
SecurityQueries of this category provide information about the security measures.

Further reading and related materials:

Reference
https://en.wikipedia.org/wiki/Principle_of_least_privilege