Goal This query identifies redundant rewrite rules within the database schema. It targets views that are inherently non-updatable (due to the presence of aggregates, joins, or set operations) but are nevertheless defined with a DO INSTEAD NOTHING rule. Since the PostgreSQL engine cannot perform DML operations on such views natively, the view is effectively read-only by definition. Consequently, the explicit rule serves no functional purpose in preventing data modification and represents superfluous schema metadata.
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 (opens in new tab)
Fixing Suggestion Drop the rules.
Data Source INFORMATION_SCHEMA+system catalog
SQL Query 
WITH non_updatable_views AS (SELECT table_schema AS schema, table_name AS view
FROM Information_schema.views
WHERE (is_insertable_into='YES' OR is_updatable='YES') AND check_option='NONE'
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)
AND (view_definition~*'(JOIN|DISTINCT|GROUP|UNION|INTERSECT|EXCEPT|HAVING|WHERE.*[_[:alnum:]]+\.[_[:alnum:]]+[[:space:]]*=[[:space:]]*[_[:alnum:]]+\.[_[:alnum:]]+|LIMIT|OFFSET|FETCH[[:space:]]FIRST)'
OR view_definition~*'(sum|count|avg|min|max|over)[[:space:]]{0,1}[(]'))
SELECT schemaname, tablename, rulename, definition   
FROM pg_rules
WHERE definition~'ON[[:space:]](INSERT|UPDATE|DELETE).*DO[[:space:]]INSTEAD[[:space:]]NOTHING'
AND (schemaname, tablename) IN (SELECT schema, view
FROM non_updatable_views)
ORDER BY schemaname, tablename, rulename;

SQL statements that help generate fixes for the identified problem.

Fix Action #1
WITH non_updatable_views AS (SELECT table_schema AS schema, table_name AS view
FROM Information_schema.views
WHERE (is_insertable_into='YES' OR is_updatable='YES') AND check_option='NONE'
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)
AND (view_definition~*'(JOIN|DISTINCT|GROUP|UNION|INTERSECT|EXCEPT|HAVING|WHERE.*[_[:alnum:]]+\.[_[:alnum:]]+[[:space:]]*=[[:space:]]*[_[:alnum:]]+\.[_[:alnum:]]+|LIMIT|OFFSET|FETCH[[:space:]]FIRST)'
OR view_definition~*'(sum|count|avg|min|max|over)[[:space:]]{0,1}[(]'))
SELECT format('DROP RULE %1$I ON %2$I.%3$I;', rulename, schemaname, tablename) AS statements
FROM pg_rules
WHERE definition~'ON[[:space:]](INSERT|UPDATE|DELETE).*DO[[:space:]]INSTEAD[[:space:]]NOTHING'
AND (schemaname, tablename) IN (SELECT schema, view
FROM non_updatable_views)
ORDER BY schemaname, tablename, rulename;

Drop the rules.

SQL Query to Generate FixDescription
WITH non_updatable_views AS (SELECT table_schema AS schema, table_name AS view
FROM Information_schema.views
WHERE (is_insertable_into='YES' OR is_updatable='YES') AND check_option='NONE'
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)
AND (view_definition~*'(JOIN|DISTINCT|GROUP|UNION|INTERSECT|EXCEPT|HAVING|WHERE.*[_[:alnum:]]+\.[_[:alnum:]]+[[:space:]]*=[[:space:]]*[_[:alnum:]]+\.[_[:alnum:]]+|LIMIT|OFFSET|FETCH[[:space:]]FIRST)'
OR view_definition~*'(sum|count|avg|min|max|over)[[:space:]]{0,1}[(]'))
SELECT format('DROP RULE %1$I ON %2$I.%3$I;', rulename, schemaname, tablename) AS statements
FROM pg_rules
WHERE definition~'ON[[:space:]](INSERT|UPDATE|DELETE).*DO[[:space:]]INSTEAD[[:space:]]NOTHING'
AND (schemaname, tablename) IN (SELECT schema, view
FROM non_updatable_views)
ORDER BY schemaname, tablename, rulename;
Drop the rules.

Collections

This query belongs to the following collections:

Find problems automatically

Queries, 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 .

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:

Derived tables

Queries of this category provide information about the derived tables (views, materialized views), which are used to implement virtual data layer.

Triggers and rules

Queries of this category provide information about triggers and rules in a database.

NameDescription
Derived tablesQueries of this category provide information about the derived tables (views, materialized views), which are used to implement virtual data layer.
Triggers and rulesQueries of this category provide information about triggers and rules in a database.