Fix #272: no longer treat main schema as a special schema

src/include/storage/postgres_catalog.hpp

@@ -31,6 +31,9 @@ class PostgresCatalog : public Catalog {
 	string GetCatalogType() override {
 		return "postgres";
 	}
+	string GetDefaultSchema() const override {
+		return default_schema.empty() ? "public" : default_schema;
+	}
 
 	optional_ptr<CatalogEntry> CreateSchema(CatalogTransaction transaction, CreateSchemaInfo &info) override;
 

src/storage/postgres_catalog.cpp

@@ -66,9 +66,6 @@ void PostgresCatalog::ScanSchemas(ClientContext &context, std::function<void(Sch
 optional_ptr<SchemaCatalogEntry> PostgresCatalog::GetSchema(CatalogTransaction transaction, const string &schema_name,
                                                             OnEntryNotFound if_not_found,
                                                             QueryErrorContext error_context) {
-	if (schema_name == DEFAULT_SCHEMA) {
-		return GetSchema(transaction, default_schema, if_not_found, error_context);
-	}
 	auto &postgres_transaction = PostgresTransaction::Get(transaction.GetContext(), *this);
 	if (schema_name == "pg_temp") {
 		return GetSchema(transaction, postgres_transaction.GetTemporarySchema(), if_not_found, error_context);

test/other.sql

@@ -164,3 +164,7 @@ INSERT INTO varchars_fixed_len VALUES ('hello'), ('world'), ('maxlength1'), ('he
 create table tbl_with_constraints(pk int primary key, c1 int not null, c2 int, c3 int not null);
 create table tbl_with_more_constraints(pk1 int, pk2 int, fk1 int references tbl_with_constraints(pk), primary key (pk1, pk2));
 create table tbl_with_unique_constraints(pk int unique, c1 int not null, c2 int, c3 int not null, unique(c2, c3));
+
+create schema main;
+create table main.main_tbl(i int);
+insert into main.main_tbl values (42), (NULL);

test/sql/storage/attach_main_schema.test

@@ -0,0 +1,28 @@
+# name: test/sql/storage/attach_main_schema.test
+# description: Test usage of the main schema in Postgres
+# group: [storage]
+
+require postgres_scanner
+
+require-env POSTGRES_TEST_DATABASE_AVAILABLE
+
+statement ok
+PRAGMA enable_verification
+
+statement ok
+ATTACH 'dbname=postgresscanner' AS s (TYPE POSTGRES)
+
+query I
+SELECT * FROM s.main.main_tbl
+----
+42
+NULL
+
+statement ok
+USE s
+
+query I
+SELECT * FROM main.main_tbl
+----
+42
+NULL