External Tables: Persistent Postgres table for managing external data queried by DuckDB readers

include/pgduckdb/pgduckdb_external_tables.hpp

@@ -0,0 +1,29 @@
+#pragma once
+
+#include <string>
+
+#include "pgduckdb/pg/declarations.hpp"
+
+namespace pgduckdb {
+
+void ValidateExternalIdentifier(const char *identifier, const char *context);
+
+std::string BuildExternalTableFunctionCall(const char *reader, const char *location, void *options);
+
+bool EnsureExternalTableLoaded(Oid relid);
+
+void ForgetLoadedExternalTable(Oid relid);
+
+void ResetLoadedExternalTableCache();
+
+bool pgduckdb_is_external_relation(Oid relation_oid);
+
+void RegisterExternalTableDependency(Oid relid);
+
+void EnsureExternalTablesCatalogExists();
+
+void UpsertExternalTableMetadata(Oid relid, const char *reader, const char *location, Datum options);
+
+void DeleteExternalTableMetadata(Oid relid);
+
+} // namespace pgduckdb

include/pgduckdb/pgduckdb_ruleutils.h

@@ -15,8 +15,9 @@ char *pgduckdb_get_tabledef(Oid relation_id);
 char *pgduckdb_get_alter_tabledef(Oid relation_oid, AlterTableStmt *alter_stmt);
 char *pgduckdb_get_rename_relationdef(Oid relation_oid, RenameStmt *rename_stmt);
 bool pgduckdb_is_not_default_expr(Node *node, void *context);
-List *pgduckdb_db_and_schema(const char *postgres_schema_name, const char *duckdb_table_am_name);
-const char *pgduckdb_db_and_schema_string(const char *postgres_schema_name, const char *duckdb_table_am_name);
+List *pgduckdb_db_and_schema(const char *postgres_schema_name, const char *duckdb_table_am_name, bool is_ddb_external);
+const char *pgduckdb_db_and_schema_string(const char *postgres_schema_name, const char *duckdb_table_am_name,
+                                          bool is_ddb_external);
 bool pgduckdb_is_duckdb_row(Oid type_oid);
 bool pgduckdb_is_unresolved_type(Oid type_oid);
 bool pgduckdb_is_fake_type(Oid type_oid);

sql/pg_duckdb--1.0.0--1.1.0.sql

@@ -0,0 +1,8 @@
+CREATE TABLE IF NOT EXISTS duckdb.external_tables (
+    relid regclass PRIMARY KEY,
+    reader TEXT NOT NULL,
+    location TEXT NOT NULL,
+    options JSONB
+);
+
+REVOKE ALL ON duckdb.external_tables FROM PUBLIC;