diff --git a/usql/usql.cpp b/usql/usql.cpp
index 4cb568f..b077639 100644
--- a/usql/usql.cpp
+++ b/usql/usql.cpp
@@ -6,9 +6,36 @@
 
 namespace usql {
 
+USql::USql() {
+	// create catalogue tables first
+
+	std::vector<std::string> k_debug_sql_commands {
+		"create table usql_tables(name varchar(32) not null, modified boolean not null)",
+		"create table usql_columns(table_name varchar(32) not null, column_name varchar(32) not null, column_type varchar(16) not null, column_length integer not null, nullable boolean not null, column_order integer not null)"
+	};
+
+	// create cataloque tables
+	for (const auto &command : k_debug_sql_commands) {
+		std::unique_ptr<Node> create_table_node = m_parser.parse(command);
+		const CreateTableNode &node = static_cast<CreateTableNode &>(*create_table_node); 
+
+		Table table{node.table_name, node.cols_defs};
+		m_tables.push_back(table);
+
+	}
+	// insert data into cataloque tables
+	for (const auto &command : k_debug_sql_commands) {
+		std::unique_ptr<Node> create_table_node = m_parser.parse(command);
+		const CreateTableNode &node = static_cast<CreateTableNode &>(*create_table_node); 
+
+		execute_create_table_sys_catalogue(node);
+	}
+}
+
 std::unique_ptr<Table> USql::execute(const std::string &command) {
 	try {
 		std::unique_ptr<Node> node = m_parser.parse(command);
+		// node->dump();
 		return execute(*node);
 
 	} catch (const std::exception &e) {
diff --git a/usql/usql.h b/usql/usql.h
index 5cd8dc8..5caa4fe 100644
--- a/usql/usql.h
+++ b/usql/usql.h
@@ -11,16 +11,16 @@
 namespace usql {
 
 class USql {
-
+	
 public:
-    USql() = default;
-
+	USql();
     std::unique_ptr<Table> execute(const std::string &command);
 
 private:
     std::unique_ptr<Table> execute(Node &node);
 
     std::unique_ptr<Table> execute_create_table(const CreateTableNode &node);
+	bool execute_create_table_sys_catalogue(const CreateTableNode &node);
     std::unique_ptr<Table> execute_create_index(const CreateIndexNode &node);
     std::unique_ptr<Table> execute_create_table_as_table(const CreateTableAsSelectNode &node);
     std::unique_ptr<Table> execute_load(const LoadIntoTableNode &node);
@@ -59,9 +59,6 @@ private:
 	void check_index_not_exists(const std::string &index_name);
 
 private:
-    Parser m_parser;
-    std::list<Table> m_tables;
-
     static void execute_distinct(SelectFromTableNode &node, Table *result);
     static void execute_order_by(SelectFromTableNode &node, Table *result);
     static void execute_offset_limit(OffsetLimitNode &node, Table *result);
@@ -97,6 +94,11 @@ private:
 	bool normalize_where(const Node *node) const;
 
     Table::rows_scanner get_iterator(Table *table, const Node *where) const;
+
+
+private:
+    Parser m_parser;
+    std::list<Table> m_tables;
 };
 
 
diff --git a/usql/usql_ddl.cpp b/usql/usql_ddl.cpp
index c6b1e18..4fcaa2c 100644
--- a/usql/usql_ddl.cpp
+++ b/usql/usql_ddl.cpp
@@ -15,10 +15,35 @@ std::unique_ptr<Table> USql::execute_create_table(const CreateTableNode &node) {
 	Table table{node.table_name, node.cols_defs};
 	m_tables.push_back(table);
 
+	execute_create_table_sys_catalogue(node);
+
 	return create_stmt_result_table(0, "table created", 0);
 }
 
 
+bool USql::execute_create_table_sys_catalogue(const CreateTableNode &node) {
+	// usql_tables 
+	auto r = execute("insert into usql_tables(name, modified) values('" + node.table_name + "', false)");
+
+	// usql_columns 
+	for(const ColDefNode & col_def : node.cols_defs) {
+		std::string i {"insert into usql_columns(table_name, column_name, column_type, column_length, nullable, column_order) values("};
+					i += "'" + node.table_name + "', ";
+					i += "'" + col_def.name + "', ";
+					i += "'" + column_type_name(col_def.type) + "', ";
+					i += std::to_string(col_def.length) + ", ";
+					i += (col_def.null ?  "true, " : "false, ");
+					i += std::to_string(col_def.order);
+					i += ")";
+
+		auto r = execute(i);
+		// r->print();
+	}
+
+	return true;
+}
+
+
 std::unique_ptr<Table> USql::execute_create_index(const CreateIndexNode &node) {
 	Table *table_def = find_table(node.table_name);				// throws exception if not found
 	ColDefNode col_def = table_def->get_column_def(node.column_name);	// throws exception if not found
@@ -57,7 +82,6 @@ std::unique_ptr<Table> USql::execute_create_table_as_table(const CreateTableAsSe
 }
 
 
-
 std::unique_ptr<Table> USql::execute_drop(const DropTableNode &node) {
 	auto name_cmp = [node](const Table& t) { return t.m_name == node.table_name; };
 
@@ -70,11 +94,13 @@ std::unique_ptr<Table> USql::execute_drop(const DropTableNode &node) {
 	throw Exception("table not found (" + node.table_name + ")");
 }
 
+
 std::unique_ptr<Table> USql::execute_set(const SetNode &node) {
 	Settings::set_setting(node.name, node.value);
 	return create_stmt_result_table(0, "set succeeded", 1);
 }
 
+
 std::unique_ptr<Table> USql::execute_show(const ShowNode &node) {
 	std::string value = Settings::get_setting(node.name);
 	return create_stmt_result_table(0, "show succeeded: " + value, 1);