PostgreSQL Design Check Queries

Catalog of PostgreSQL queries for finding information about a PostgreSQL database and its design problems

	Choose collection:
AND	Choose query type:
AND	Choose query reliability:
AND	Choose category:	Queries of this catergory provide information about stubs (piece of code used to stand in for some other programming functionality).
AND	Choose data source:	From where does the query gets its information?
AND	Enter string:
AND	Has fixing queries?

All the queries about database objects contain a subcondition to exclude from the result information about the system catalog.
Although the statements use SQL constructs (common table expressions; NOT in subqueries) that could cause performance problems in case of large datasets it shouldn't be a problem in case of relatively small amount of data, which is in the system catalog of a database.
Statistics about the catalog content and project home in GitHub that has additional information.

There are 7 queries.

Seq nr	Name▲	Goal	Type	Data source	Last update	License	...
1	CHECK constraint cardinality is zero	Write correct constraints. Usually the constraint expression should refer to at least one column. A domain constraint expression should refer to the stub VALUE. For instance, the constraint CHECK(1=0) that is associated with a table T would prevent adding any rows to T. The value of the Boolean expression of this constraint is always FALSE.	Problem detection	INFORMATION_SCHEMA+system catalog base tables	2022-04-22 17:06	MIT License	View
2	Enumerated types with zero or one value	Fidn enumerated types with zero or one value. Type is a named finite set of values. The empty set is a set. A set with one value is a set. Thus, types with zero or one value are legal. In practical terms each type, usually, should contain at least two values.	Problem detection	INFORMATION_SCHEMA+system catalog base tables	2021-02-25 17:30	MIT License	View
3	Invocation of a system-defined routine without providing any arguments	Find user-defined routines that contain an invocation of a system-defined function without providing any argument. The query considers all aggregate functions as well as some popular scalar functions.	Problem detection	INFORMATION_SCHEMA+system catalog base tables	2023-12-22 13:00	MIT License	View
4	Perhaps a routine does not have a real task	Find the routines where the only action is to return an argument value, a constant value, NULL or return the value of OLD or NEW variable in case of trigger functions.	Problem detection	INFORMATION_SCHEMA+system catalog base tables	2021-11-05 12:09	MIT License	View
5	Routines without an action	Find routines that body does not contain any action.	Problem detection	INFORMATION_SCHEMA+system catalog base tables	2021-11-05 12:14	MIT License	View
6	Tables without columns	Do not have in a database elements that are not useful. PostgreSQL permits tables with no columns. Such tables can be used to implement Boolean variables (tables TABLE_DEE and TABLE_DUM). On the other hand, such tables might be a result of database evolution, where developers have not noticed that they have dropped all the columns of a table or have not noticed that they have created such a table in the first place.	Problem detection	INFORMATION_SCHEMA+system catalog base tables	2021-02-25 17:29	MIT License	View
7	User-defined non-trigger routines without parameters	Find user-defined non-trigger routines with no parameters.	General	INFORMATION_SCHEMA+system catalog base tables	2021-11-03 20:05	MIT License	View