Per-attach CTID scan

src/include/postgres_utils.hpp

@@ -57,6 +57,8 @@ struct PostgresCopyState {
 
 enum class PostgresIsolationLevel { READ_COMMITTED, REPEATABLE_READ, SERIALIZABLE };
 
+enum class PostgresUseCtidScan : uint8_t { DEFAULT, ENABLED, DISABLED };
+
 class PostgresUtils {
 public:
 	static PGconn *PGConnect(const string &dsn, const string &attach_path);

src/include/storage/postgres_catalog.hpp

@@ -33,6 +33,7 @@ class PostgresCatalog : public Catalog {
 	string attach_path;
 	AccessMode access_mode;
 	PostgresIsolationLevel isolation_level;
+	PostgresUseCtidScan use_ctid_scan = PostgresUseCtidScan::DEFAULT;
 
 public:
 	void Initialize(bool load_builtin) override;

src/postgres_scanner.cpp

@@ -121,6 +121,10 @@ void PostgresScanFunction::PrepareBind(PostgresVersion version, ClientContext &c
 	if (context.TryGetCurrentSetting("pg_use_ctid_scan", pg_use_ctid_scan)) {
 		use_ctid_scan = BooleanValue::Get(pg_use_ctid_scan);
 	}
+	auto pg_catalog = bind_data.GetCatalog();
+	if (pg_catalog && pg_catalog->use_ctid_scan != PostgresUseCtidScan::DEFAULT) {
+		use_ctid_scan = pg_catalog->use_ctid_scan == PostgresUseCtidScan::ENABLED;
+	}
 	if (bind_data.use_text_protocol) {
 		// ctid scan is only supported for binary copy
 		use_ctid_scan = false;

src/postgres_storage.cpp

@@ -22,6 +22,7 @@ static unique_ptr<Catalog> PostgresAttach(optional_ptr<StorageExtensionInfo> sto
 	PostgresIsolationLevel isolation_level = PostgresIsolationLevel::REPEATABLE_READ;
 	string secret_storage_table_name;
 	bool secret_storage_table_specified_explicitly = false;
+	PostgresUseCtidScan use_ctid_scan = PostgresUseCtidScan::DEFAULT;
 	for (auto &entry : attach_options.options) {
 		auto lower_name = StringUtil::Lower(entry.first);
 		if (lower_name == "secret") {
@@ -45,15 +46,21 @@ static unique_ptr<Catalog> PostgresAttach(optional_ptr<StorageExtensionInfo> sto
 		} else if (lower_name == "secret_storage_table") {
 			secret_storage_table_name = entry.second.ToString();
 			secret_storage_table_specified_explicitly = true;
+		} else if (lower_name == "use_ctid_scan") {
+			use_ctid_scan = BooleanValue::Get(entry.second.DefaultCastAs(LogicalType::BOOLEAN))
+			                    ? PostgresUseCtidScan::ENABLED
+			                    : PostgresUseCtidScan::DISABLED;
 		} else {
 			throw BinderException("Unrecognized option for Postgres attach: %s", entry.first);
 		}
 	}
 	SecretStorageTable secret_storage_table(std::move(secret_storage_table_name),
 	                                        secret_storage_table_specified_explicitly);
-	return make_uniq<PostgresCatalog>(context, db, std::move(attach_path), attach_options.access_mode,
-	                                  std::move(schema_to_load), isolation_level, secret_name,
-	                                  std::move(secret_storage_table));
+	auto catalog = make_uniq<PostgresCatalog>(context, db, std::move(attach_path), attach_options.access_mode,
+	                                          std::move(schema_to_load), isolation_level, secret_name,
+	                                          std::move(secret_storage_table));
+	catalog->use_ctid_scan = use_ctid_scan;
+	return catalog;
 }
 
 static unique_ptr<TransactionManager> PostgresCreateTransactionManager(optional_ptr<StorageExtensionInfo> storage_info,

test/sql/storage/attach_use_ctid_scan.test

@@ -0,0 +1,73 @@
+# name: test/sql/storage/attach_use_ctid_scan.test
+# description: Test the per-attach use_ctid_scan option overriding the global pg_use_ctid_scan setting
+# group: [storage]
+
+require postgres_scanner
+
+require-env POSTGRES_TEST_DATABASE_AVAILABLE
+
+statement ok
+PRAGMA enable_verification
+
+# per-attach option disables ctid scan even though the global setting defaults to true
+statement ok
+SET pg_use_ctid_scan=true;
+
+statement ok
+ATTACH 'dbname=postgresscanner' AS s (TYPE POSTGRES, USE_CTID_SCAN false)
+
+query I
+SELECT * FROM s.pg_giant_numeric
+----
+0.0
+1.0000000000000002e+32
+-1.234567891234568e+26
+
+statement ok
+DETACH s
+
+# per-attach option enables ctid scan even though the global setting is false (override works both ways)
+statement ok
+SET pg_use_ctid_scan=false;
+
+statement ok
+ATTACH 'dbname=postgresscanner' AS s (TYPE POSTGRES, USE_CTID_SCAN true)
+
+query I
+SELECT * FROM s.pg_giant_numeric
+----
+0.0
+1.0000000000000002e+32
+-1.234567891234568e+26
+
+statement ok
+DETACH s
+
+# when omitted, behavior follows the global setting (here: false) and still produces correct results
+statement ok
+ATTACH 'dbname=postgresscanner' AS s (TYPE POSTGRES)
+
+query I
+SELECT * FROM s.pg_giant_numeric
+----
+0.0
+1.0000000000000002e+32
+-1.234567891234568e+26
+
+statement ok
+DETACH s
+
+statement ok
+SET pg_use_ctid_scan=true;
+
+# boolean-typed values are accepted
+statement ok
+ATTACH 'dbname=postgresscanner' AS s (TYPE POSTGRES, USE_CTID_SCAN 1)
+
+statement ok
+DETACH s
+
+# a non-boolean value raises a clear error
+statement error
+ATTACH 'dbname=postgresscanner' AS s (TYPE POSTGRES, USE_CTID_SCAN 'not_a_bool')
+----