FOR UPDATE is not needed if there is no FROM clause in the SELECT statement

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Goal Find routines that use SELECT … FOR UPDATE without selecting rows from a specific table. For instance: SELECT 'text' AS v FOR UPDATE;
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 Drop the routine and recreate it.
Data Source INFORMATION_SCHEMA+system catalog
SQL Query 
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( regexp_replace(pg_get_functiondef(pg_proc.oid),'<','<','g'),'[\r\n]','
','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_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) 
AND pg_get_functiondef(pg_proc.oid)~*'[[:space:]]select[[:space:]][^;]+for[[:space:]]+update[[:space:]]*[;]' 
AND pg_get_functiondef(pg_proc.oid)!~*'[[:space:]]select[[:space:]][^;]*[[:space:]]from[[:space:]][^;]*for[[:space:]]+update[[:space:]]*[;]'
ORDER BY routine_schema, routine_name, parameters;

SQL statements that help generate fixes for the identified problem.

SQL Query to Generate FixDescription
WITH unnecessary_for_update AS (SELECT 
  pg_namespace.nspname AS routine_schema, 
  pg_proc.proname AS routine_name, 
  pg_get_function_identity_arguments(pg_proc.oid) AS parameters
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_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) 
AND pg_get_functiondef(pg_proc.oid)~*'[[:space:]]select[[:space:]][^;]+for[[:space:]]+update[[:space:]]*[;]' 
AND pg_get_functiondef(pg_proc.oid)!~*'[[:space:]]select[[:space:]][^;]*[[:space:]]from[[:space:]][^;]*for[[:space:]]+update[[:space:]]*[;]')
SELECT format('DROP ROUTINE %1$s.%2$s(%3$s);', routine_schema, routine_name, parameters) AS statements
FROM unnecessary_for_update
ORDER BY routine_schema, routine_name, parameters;
Drop the routine.
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
Concurrency controlQueries of this category provide information about concurrency control.
Does not work in some earlier PostgreSQL versionQueries of this category provide information that was not available in some earlier PostgreSQL version
User-defined routinesQueries of this category provide information about the user-defined routines