diff --git a/brmbar3/SQL-schema-v001.sql b/brmbar3/SQL-schema-v001.sql
new file mode 100644
index 0000000..44b9693
--- /dev/null
+++ b/brmbar3/SQL-schema-v001.sql
@@ -0,0 +1,59 @@
+--RESET search_path;
+SELECT pg_catalog.set_config('search_path', '', false);
+-- intoduce implementation schema
+CREATE SCHEMA IF NOT EXISTS brmbar_implementation;
+-- version table (with initialization)
+CREATE TABLE IF NOT EXISTS brmbar_implementation.brmbar_schema (
+	ver INTEGER NOT NULL
+);
+DO $$
+DECLARE v INTEGER;
+BEGIN
+	SELECT ver FROM brmbar_implementation.brmbar_schema INTO v;
+	IF v IS NULL THEN
+		INSERT INTO brmbar_implementation.brmbar_schema (ver) VALUES (1);
+	END IF;
+END;
+$$;
+
+CREATE OR REPLACE FUNCTION brmbar_implementation.has_exact_schema_version(
+	IN i_ver INTEGER NOT NULL
+) RETURNS INTEGER
+VOLATILE  NOT LEAKPROOF  LANGUAGE plpgsql AS $$
+DECLARE
+	v_ver INTEGER;
+BEGIN
+	SELECT ver INTO STRICT v_ver FROM brmbar_implementation.brmbar_schema;
+	IF v_ver IS NULL or v_ver <> i_ver THEN
+		RAISE EXCEPTION 'Invalid brmbar schema version';
+	END IF;
+	RETURN v_ver;
+/*
+EXCEPTION
+	WHEN NO_DATA_FOUND THEN
+		RAISE EXCEPTION 'PID % not found';
+	WHEN TOO_MANY_ROWS THEN
+		RAISE EXCEPTION 'PID % not unique';
+*/
+END;
+$$;
+
+CREATE OR REPLACE FUNCTION brmbar_implementation.upgrade_schema_version_to(
+	IN i_ver INTEGER NOT NULL
+) RETURNS INTEGER
+VOLATILE  NOT LEAKPROOF  LANGUAGE plpgsql AS $$
+DECLARE
+	v_ver INTEGER;
+BEGIN
+	SELECT brmbar_implementation.has_exact_schema_version(i_ver) INTO v_ver;
+	IF v_ver + 1 = i_ver THEN
+		UPDATE brmbar_implementation.brmbar_schema SET ver = i_ver;
+	ELSE
+		RAISE EXCEPTION 'Invalid brmbar schema version';
+	END IF;
+	RETURN i_ver;
+END;
+$$;
+
+-- vim: set ft=plsql :
+