The list of all the queries

No need to use to_date or to_timestamp function

Query goal: Find expressions where a date literal with the ISO format is converted to date/timestamp by using to_date or to_timestamp function.
Query type: Problem detection (Each row in the result could represent a flaw in the design)
Query reliability: Low (Many false-positive results)
Query license: MIT License
Fixing suggestion: ISO format is the default and the use of the function is in this case not needed. Thus, instead of reg_time>=to_timestamp('2010-01-01 00:00','YYYY-MM-DD HH24:MI') one can write reg_time>='2010-01-01 00:00'
Data source: INFORMATION_SCHEMA+system catalog
SQL query: Click on query to copy it

WITH expressions AS (select 
n.nspname as schema,
c.relname || '.' || o.conname as name, 
substring(pg_get_constraintdef(o.oid),7) as expression,
'TABLE CHECK' AS type
from pg_constraint o inner join pg_class c on c.oid = o.conrelid
inner join pg_namespace n on n.oid=c.relnamespace
where o.contype ='c' 
and n.nspname not in (select schema_name
from information_schema.schemata
where schema_name<>'public' and
schema_owner='postgres' and schema_name is not null)
union select n.nspname as schema,
t.typname || '.' || o.conname as name, 
substring(pg_get_constraintdef(o.oid),7) as expression,
'DOMAIN CHECK' AS type
from pg_constraint o inner join pg_type t on t.oid = o.contypid
inner join pg_namespace n on n.oid=t.typnamespace
where o.contype ='c' and n.nspname not in (select schema_name
from information_schema.schemata
where schema_name<>'public' and
schema_owner='postgres' and schema_name is not null)
UNION SELECT c.table_schema, t.table_name || '.'|| c.column_name, c.column_default AS expression,
'COLUMN DEFAULT'AS type
FROM information_schema.columns AS c 
INNER JOIN INFORMATION_SCHEMA.tables AS t  USING (table_schema, table_name)
WHERE c.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 column_default IS NOT NULL
UNION SELECT domain_schema, domain_name, domain_default AS expression,
'DOMAIN DEFAULT' AS type
FROM information_schema.domains 
WHERE domain_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 domain_default IS NOT NULL
UNION SELECT trigger_schema, event_object_table || '.' || trigger_name, action_condition, 'TRIGGER WHEN' AS type
FROM INFORMATION_SCHEMA.triggers
WHERE action_condition IS NOT NULL
UNION SELECT schemaname, tablename || '.' || rulename, definition, 'RULE WHERE' AS type
FROM pg_catalog.pg_rules
WHERE schemaname NOT IN (SELECT schema_name
FROM INFORMATION_SCHEMA.schemata
WHERE schema_name<>'public' AND
schema_owner='postgres' AND schema_name IS NOT NULL)
UNION SELECT  table_schema, table_name, regexp_replace(view_definition,'[\r\n]','<br>','g') AS view_definition, 'VIEW SUBQUERY' AS type
FROM information_schema.views
WHERE 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)
UNION SELECT schemaname, matviewname, regexp_replace(definition,'[\r\n]','<br>','g') AS definition, 'MATERIALIZED VIEW SUBQUERY' AS type
FROM pg_catalog.pg_matviews
UNION SELECT pg_namespace.nspname AS routine_schema,  pg_proc.proname || '(' || pg_get_function_identity_arguments(pg_proc.oid)  || ')' AS routine_name,  regexp_replace(pg_proc.prosrc,'[\r\n]','<br>','g')  AS routine_src, 'ROUTINE BODY' AS type
FROM pg_catalog.pg_proc, pg_catalog.pg_namespace
WHERE pg_proc.pronamespace = pg_namespace.oid 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 NOT EXISTS (SELECT 1
FROM pg_catalog.pg_depend d 
WHERE EXISTS (SELECT 1 FROM pg_catalog.pg_extension e WHERE d.refobjid=e.oid) AND
d.objid=pg_proc.oid))
SELECT schema, name AS object_identifier, type AS object_type, regexp_replace(expression,'(to_date|to_timestamp|to_char|to_number)','<b>\1</b>','g') AS suspected_expression
FROM expressions
WHERE expression ~*'(to_date|to_timestamp)[(][^)]*YYYY-MM-DD'
ORDER BY schema, type, 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 .

Categories where the query belongs to

Category nameCategory description
CHECK constraintsQueries of this category provide information about CHECK constraints.
Comfortability of database evolutionQueries of this category provide information about the means that influence database evolution.
Default valueQueries of this catergory provide information about the use of default values.
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.
User-defined routinesQueries of this category provide information about the user-defined routines

Reference materials for further reading

Reference
https://www.postgresql.org/docs/current/datatype-datetime.html
https://en.wikipedia.org/wiki/ISO_8601

The list of all the queries