diff --git a/lib/tooling/schema/discovery.py b/lib/tooling/schema/discovery.py
index 571afa6..250de7d 100644
--- a/lib/tooling/schema/discovery.py
+++ b/lib/tooling/schema/discovery.py
@@ -143,6 +143,14 @@ def get_prop(expr, Type):
     es = expr.args['properties'].expressions
     return next((e for e in es if isinstance(e, Type)))
 
+def create_function(expr: Expression, command_e: str) -> Stmt.Op:
+    match = re.search(r"FUNCTION\s+(?:(\w+)\.)?(\w+)\s*\(", command_e, re.IGNORECASE)
+    if not match:
+        raise TypeError(f'unknown {repr(e)}')
+    s_name = match.group(1) if match.group(1) else None
+    t_name = match.group(2)
+    return Stmt.CreateFunction(expr, s_name, t_name)
+
 def expr_as_op(expr: Expression) -> Optional[Stmt.Op]:
     match expr:
         case sql_expr.Create(kind="SCHEMA", this=schema_def):
@@ -171,12 +179,9 @@ def expr_as_op(expr: Expression) -> Optional[Stmt.Op]:
         case sql_expr.Command(this="CREATE", expression=e):
             match re.findall(f'\w+', e.lower()):
                 case ['function', *_]:
-                    match = re.search(r"FUNCTION\s+(?:(\w+)\.)?(\w+)\s*\(", e, re.IGNORECASE)
-                    if not match:
-                        raise TypeError(f'unknown {repr(e)}')
-                    s_name = match.group(1) if match.group(1) else None
-                    t_name = match.group(2)
-                    return Stmt.CreateFunction(expr, s_name, t_name)
+                    return create_function(expr, e)
+                case ['or', 'replace', 'function', *_]:
+                    return create_function(expr, e)
                 case ['type', s_name, t_name, 'as', *_]:
                     return Stmt.CreateType(expr, s_name, t_name)
                 case ['type', t_name, 'as', *_]:
diff --git a/lib/tooling/schema/tests/test_discovery.py b/lib/tooling/schema/tests/test_discovery.py
index 161c113..d15e61b 100644
--- a/lib/tooling/schema/tests/test_discovery.py
+++ b/lib/tooling/schema/tests/test_discovery.py
@@ -28,7 +28,7 @@ def test_expr_as_op(snapshot, sql: str):
     operations = sql_as_operations(sql)
     snapshot.assert_match(pformat(operations, width=150), 'schema')
 
-def test_function():
+def test_create_function():
     sql = \
         "CREATE FUNCTION a.c(input TEXT) RETURNS TEXT $$ BEGIN RETURN ''; END; $$ LANGUAGE plpgsql"
     schema = sql_as_operations(sql)
@@ -36,6 +36,14 @@ def test_function():
     assert create_function.schema_name == 'a'
     assert create_function.type_name == 'c'
 
+def test_create_or_replace_function():
+    sql = \
+        "CREATE OR REPLACE FUNCTION a.c(input TEXT) RETURNS TEXT $$ BEGIN RETURN ''; END; $$ LANGUAGE plpgsql"
+    schema = sql_as_operations(sql)
+    create_function = next(o for o in schema.operations)
+    assert create_function.schema_name == 'a'
+    assert create_function.type_name == 'c'
+
 def test_schema_for_parition():
     sql = \
         "CREATE TABLE a.c PARTITION OF b.a FOR VALUES WITH (MODULUS 8, REMAINDER 0)"
diff --git a/sql/nsw_gnb/schema/001_APPLY_init.sql b/sql/nsw_gnb/schema/001_APPLY_init.sql
index d6e2615..6230523 100644
--- a/sql/nsw_gnb/schema/001_APPLY_init.sql
+++ b/sql/nsw_gnb/schema/001_APPLY_init.sql
@@ -66,3 +66,9 @@ SELECT DISTINCT ON (property_id, strata_lot_number)
   LEFT JOIN nsw_gnb.street USING (street_id, locality_id)
   LEFT JOIN nsw_gnb.locality USING (locality_id);
 
+CREATE OR REPLACE FUNCTION nsw_gnb.addr_str(a nsw_gnb.full_property_address) RETURNS TEXT
+LANGUAGE SQL IMMUTABLE PARALLEL SAFE AS $$
+  SELECT (a.street_number || ' ' || a.street_name || ' ' || a.locality_name || ' ' || a.postcode);
+$$;
+
+