From ca98087734df0cddefd9610b7c23be8d1b758969 Mon Sep 17 00:00:00 2001 From: Amit Langote Date: Fri, 17 Apr 2026 08:42:19 +0900 Subject: [PATCH v2] Reject invalid databases in pg_get_database_ddl() An invalid database has datconnlimit set to -2. pg_get_database_ddl() emits this verbatim as CONNECTION LIMIT = -2, which ALTER DATABASE rejects. Error out early instead. Reported-by: Lakshmi N Author: Lakshmi N Reviewed-by: Amit Langote Discussion: https://postgr.es/m/CA+3i_M8m1k2gFch+tU0JmAQh9FRV+pFrfTXDrJo+BqmwsTmOhg@mail.gmail.com --- src/backend/utils/adt/ddlutils.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/src/backend/utils/adt/ddlutils.c b/src/backend/utils/adt/ddlutils.c index c4f9f86c43e..3921ed1fa6a 100644 --- a/src/backend/utils/adt/ddlutils.c +++ b/src/backend/utils/adt/ddlutils.c @@ -887,6 +887,17 @@ pg_get_database_ddl_internal(Oid dbid, bool pretty, dbform = (Form_pg_database) GETSTRUCT(tuple); dbname = pstrdup(NameStr(dbform->datname)); + /* + * Reject invalid databases: datconnlimit = -2 would be emitted as + * CONNECTION LIMIT = -2, which cannot be executed. + */ + if (database_is_invalid_form(dbform)) + ereport(ERROR, + (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE), + errmsg("cannot generate DDL for invalid database \"%s\"", + dbname), + errhint("Use DROP DATABASE to drop invalid databases."))); + /* * We don't support generating DDL for system databases. The primary * reason for this is that users shouldn't be recreating them. -- 2.47.3