PostgreSQL Query Catalog

Avoid creating user-defined routines that have the same name as some extension routine because it may cause confusion.

This query analyzes the semantic consistency of routine signatures by identifying named input parameters that share an identical identifier but possess divergent data types across different routines. While this pattern is a prerequisite for valid routine overloading (polymorphism), it can also indicate a lack of standardization in the data dictionary. For example, using the parameter name status to denote an INTEGER in one context and TEXT in another creates ambiguity regarding the parameter's expected domain. The query results should be audited to distinguish intentional overloading from naming inconsistencies.

Make sure that there is genuine overloading instead of duplication or dead code. "In some programming languages, function overloading or method overloading is the ability to create multiple functions of the same name with different implementations." (Wikipedia) In PostgreSQL one can do it automagically by having multiple routines with the same name but different parameters in the same schema.

Routines in the same schema that have the same name and that have parameters with different types or different number of parameters are not considered to be in conflict at the creation time. However, if defaults are provided in the definition of parameters, then these routines might be conflict during runtime.

Avoid creating user-defined routines that have the same name as some system-defined routine because it may cause confusion.

This query audits the schema for semantic ambiguity by identifying pairs of routine names (functions, procedures) that exhibit high textual similarity but are not identical. It filters for name pairs with a Levenshtein edit distance of exactly one (less than two, but excluding equality). This specific filter targets typographical errors (e.g., calc_tax vs. calc_tux) or inconsistent singular/plural naming (e.g., get_user vs. get_users), while correctly ignoring valid method overloading where names are identical.