Find routine parameters that based on the name seem to hold truth values. Find parameters that name starts with "is_" or "has_" or "can_" or "on_" and that do not have Boolean type.
Notes
The query does not consider objects that are a part of an extension. There could be multiple routines with the same name but with different parameters in the same schema (overloading). Thus, for the unique identification of the routine it is necessary to present also its parameters in addition to the schema name and routine name.
Type
Problem detection (Each row in the result could represent a flaw in the design)
WITH params AS (SELECT
specific_schema AS routine_schema,
regexp_replace(specific_name,'_[0-9]*$','') AS routine_name,
pg_get_function_identity_arguments(translate(substring(specific_name,'_[0-9]+$'),'_','')::int::oid) AS parameters,
parameter_name,
ordinal_position,
data_type
FROM
information_schema.parameters
WHERE specific_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 NOT EXISTS (SELECT 1
FROM pg_catalog.pg_depend d inner join pg_catalog.pg_proc pc ON d.objid=pc.oid
WHERE EXISTS (SELECT 1 FROM pg_catalog.pg_extension e WHERE d.refobjid=e.oid) AND
pc.proname || '_' || pc.oid = parameters.specific_name))
SELECT routine_schema, routine_name, parameters, parameter_name, ordinal_position, data_type
FROM params
WHERE parameter_name~*'^(is|has|can|on)_'
AND data_type<>'boolean'
ORDER BY routine_schema, routine_name, parameters, ordinal_position;
Collections
This query belongs to the following collections:
Name
Description
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 .
Lexicon bad smells and linguistic antipatterns
Queries made to find the occurrences of lexicon bad smells and linguistic antipatterns
Categories
This query is classified under the following categories:
Name
Description
Boolean data
Queries of this category provide information about truth-values data that is kept in the database.
Data types
Queries of this category provide information about the data types and their usage.
Result quality depends on names
Queries of this category use names (for instance, column names) to try to guess the meaning of a database object. Thus, the goodness of names determines the number of false positive and false negative results.
User-defined routines
Queries of this category provide information about the user-defined routines
Further reading and related materials:
Reference
Linguistic antipattern "D.2 Name suggests boolean but type is not": Arnaoudova, V., Di Penta, M., Antoniol, G., 2016. Linguistic antipatterns: What they are and how developers perceive them. Empirical Software Engineering, 21(1), pp.104-158.