42723 — Duplicate function

At a glance

42723 is duplicate_function: a function definition repeats the same schema, name, and input argument types. Output types do not create another overload.

Meaning

The fixed catalog path reports function "%s" already exists with same argument types. Inspect pg_proc, pg_get_function_identity_arguments, and the result contract. This is a definition collision, unlike 42725, which occurs when call resolution has multiple candidates; the selected autocommit error leaves IDLE.

Diagnosis

Inspect pg_proc with pg_get_function_identity_arguments and make the schema explicit. Decide whether the migration intends a new input signature or replacement of an owned function; output types do not disambiguate identity.

Response

Use a new input signature for a genuinely different API. Use CREATE OR REPLACE FUNCTION only when replacing the owned function is intentional and its return contract stays compatible; it is not a safe input-type migration. In an explicit transaction, the duplicate definition leaves INERROR; roll back or return to a suitable savepoint before retrying. The selected autocommit path returns to IDLE.

Observed diagnostics

The pg_proc.c group is explicit ERROR with the fixed primary template and no detail or hint.

Representative case

The runner creates duplicate_function(integer), repeats that signature, then deliberately uses CREATE OR REPLACE and verifies the result 2.

CREATE FUNCTION syntax_schema.duplicate_function(integer) RETURNS integer LANGUAGE SQL AS 'SELECT $1';
CREATE FUNCTION syntax_schema.duplicate_function(integer) RETURNS integer LANGUAGE SQL AS 'SELECT $1';
CREATE OR REPLACE FUNCTION syntax_schema.duplicate_function(integer) RETURNS integer LANGUAGE SQL AS 'SELECT $1 + 1';
SELECT syntax_schema.duplicate_function(1);

The selected 18.6 and 10.21 runs passed SQLSTATE, severity, state/recovery, repair, cleanup, and isolated-target stop assertions. See case JSON and authored evidence; private manifest and registry hashes are recorded there.

Versions

The locked catalogue contains this condition from the 7.4 presence bound through the listed snapshots. The selected natural case passed on PostgreSQL 18.6 and 10.21; that bounded result does not infer every intermediate release or every source branch.

Related

• 42725
• 42883

Sources

• src.errcodes.REL_18_6 — fixed definition at 724edf9bde9d356724ad384a2e196edc3c9f80f7; SHA-256 6e8de346643ba84aa3c9c6a73360acfc7b2dfb89162c06c08ce9bf5bcd5bbcba (source).
• src.duplicate-function.18.6 — src/backend/catalog/pg_proc.c lines 400–403 at 724edf9bde9d356724ad384a2e196edc3c9f80f7; blob SHA-256 77a883995e5fadf17fae68722043beb43115e685e8082b2b7256d92312528a5a (source).
• src.duplicate-function.10.23 — src/backend/catalog/pg_proc.c lines 398–401 at 02991e79f8f58bc208f05dcc8af0c62dbe0a6ea4; blob SHA-256 96ddd186536c24018d3e29fd7e8f7384543c89ede83c81f673dc013fdd23b0fe (source).
• src.calls.REL_18_6 / src.calls.REL_10_23 — fixed call scans, SHA-256 9ee8a0e81d8f0825c5c1ae45583439859a26e602bdd4ce2f2a62aa278867ccbf / 00d16d3eb01b71ccf1b245c8f3102f9d0ec9f36fb02777b8dd1b99fcb263040c.
• manifest.42723 / snippet-registry.42723 — hashes are recorded in evidence/42723.json and each runtime record.