The list of all the queries

IS NOT DISTINCT FROM in routines

Query goal: Avoid using IS NOT DISTINCT FROM because it makes the query planner to avoid using an index.
Query type: Problem detection (Each row in the result could represent a flaw in the design)
Query reliability: High (Few or no false-positive results)
Query license: MIT License
Data source: INFORMATION_SCHEMA+system catalog
SQL query: Click on query to copy it

SELECT 
  pg_namespace.nspname AS routine_schema, 
  pg_proc.proname AS routine_name, 
  pg_get_function_identity_arguments(pg_proc.oid) AS parameters,
  CASE WHEN pg_proc.prokind='f' THEN 'FUNCTION'
  WHEN pg_proc.prokind='p' THEN 'PROCEDURE'
  WHEN pg_proc.prokind='w' THEN 'WINDOW FUNCTION' END AS routine_type,
 regexp_replace(pg_get_functiondef(pg_proc.oid),'[\r\n]','<br>','g')  AS routine_src
FROM 
  pg_catalog.pg_proc, 
  pg_catalog.pg_namespace
WHERE 
  pg_proc.pronamespace = pg_namespace.oid
  AND  pg_proc.prokind<>'a'
 AND pg_proc.proname NOT IN ('f_assume_you_must_use_files', 'f_check_format_comma_separated_list', 'f_check_password', 'f_default_value_with_no_match') AND 
 pg_get_functiondef(pg_proc.oid)~*'^.*is[[:space:]]+not[[:space:]]+distinct[[:space:]]+from.*$' 
AND pg_namespace.nspname NOT IN (SELECT schema_name
FROM INFORMATION_SCHEMA.schemata
WHERE schema_name<>'public' AND
schema_owner='postgres' AND schema_name IS NOT NULL)
ORDER BY routine_schema, routine_name;

Collections where the query belongs to

Collection nameCollection description
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 .
Find problems by overviewQueries that results point to different aspects of database that might have problems. A human reviewer has to decide based on the results as to whether there are problems or not .

Categories where the query belongs to

Category nameCategory description
PerformanceQueries of this category provide information about indexes in a database.
User-defined routinesQueries of this category provide information about the user-defined routines

Reference materials for further reading

Reference
https://philbooth.me/blog/nine-ways-to-shoot-yourself-in-the-foot-with-postgresql (problem 9)
https://modern-sql.com/caniuse/is-distinct-from

The list of all the queries