diff --git a/src/test/regress/expected/create_operator.out b/src/test/regress/expected/create_operator.out
index 8656864..2e6c764 100644
--- a/src/test/regress/expected/create_operator.out
+++ b/src/test/regress/expected/create_operator.out
@@ -29,3 +29,145 @@ CREATE OPERATOR #%# (
 -- Test comments
 COMMENT ON OPERATOR ###### (int4, NONE) IS 'bad right unary';
 ERROR:  operator does not exist: integer ######
+-- Show deprecated message. => is deprecated now
+CREATE OPERATOR => (
+   leftarg = int8,		-- right unary
+   procedure = numeric_fac
+);
+WARNING:  => is deprecated as an operator name
+DETAIL:  This name may be disallowed altogether in future versions of PostgreSQL.
+-- Should fail. CREATE OPERATOR requires USAGE on SCHEMA
+BEGIN TRANSACTION;
+CREATE ROLE regress_rol_op1;
+CREATE SCHEMA schema_op1;
+GRANT USAGE ON SCHEMA schema_op1 TO PUBLIC;
+REVOKE USAGE ON SCHEMA schema_op1 FROM regress_rol_op1;
+SET ROLE regress_rol_op1;
+CREATE OPERATOR schema_op1.#*# (
+   leftarg = int8,		-- right unary
+   procedure = numeric_fac
+);
+ERROR:  permission denied for schema schema_op1
+ROLLBACK;
+-- Should fail. SETOF type functions not allowed as argument (testing leftarg)
+BEGIN TRANSACTION;
+CREATE OPERATOR #*# (
+   leftarg = SETOF int8,
+   procedure = numeric_fac
+);
+ERROR:  SETOF type not allowed for operator argument
+ROLLBACK;
+-- Should fail. SETOF type functions not allowed as argument (testing rightarg)
+BEGIN TRANSACTION;
+CREATE OPERATOR #*# (
+   rightarg = SETOF int8,
+   procedure = numeric_fac
+);
+ERROR:  SETOF type not allowed for operator argument
+ROLLBACK;
+-- Should work. Sample text-book case
+BEGIN TRANSACTION;
+CREATE OR REPLACE FUNCTION fn_op2(boolean, boolean)
+RETURNS boolean AS $$
+    SELECT NULL::BOOLEAN;
+$$ LANGUAGE sql IMMUTABLE;
+CREATE OPERATOR === (
+    LEFTARG = boolean,
+    RIGHTARG = boolean,
+    PROCEDURE = fn_op2,
+    COMMUTATOR = ===,
+    NEGATOR = !==,
+    RESTRICT = contsel,
+    JOIN = contjoinsel,
+    SORT1, SORT2, LTCMP, GTCMP, HASHES, MERGES
+);
+ROLLBACK;
+-- Should fail. Invalid attribute
+CREATE OPERATOR #@%# (
+   leftarg = int8,		-- right unary
+   procedure = numeric_fac,
+   invalid_att = int8
+);
+WARNING:  operator attribute "invalid_att" not recognized
+-- Should fail. At least leftarg or rightarg should be mandatorily specified
+CREATE OPERATOR #@%# (
+   procedure = numeric_fac
+);
+ERROR:  at least one of leftarg or rightarg must be specified
+-- Should fail. Procedure should be mandatorily specified
+CREATE OPERATOR #@%# (
+   leftarg = int8
+);
+ERROR:  operator procedure must be specified
+-- Should fail. CREATE OPERATOR requires USAGE on TYPE
+BEGIN TRANSACTION;
+CREATE ROLE regress_rol_op3;
+CREATE TYPE type_op3 AS ENUM ('new', 'open', 'closed');
+CREATE FUNCTION fn_op3(type_op3, int8)
+RETURNS int8 AS $$
+    SELECT NULL::int8;
+$$ LANGUAGE sql IMMUTABLE;
+REVOKE USAGE ON TYPE type_op3 FROM regress_rol_op3;
+REVOKE USAGE ON TYPE type_op3 FROM PUBLIC;  -- Need to do this so that regress_rol_op3 is not allowed USAGE via PUBLIC
+SET ROLE regress_rol_op3;
+CREATE OPERATOR #*# (
+   leftarg = type_op3,
+   rightarg = int8,
+   procedure = fn_op3
+);
+ERROR:  permission denied for type type_op3
+ROLLBACK;
+-- Should fail. CREATE OPERATOR requires USAGE on TYPE (need to check separately for rightarg)
+BEGIN TRANSACTION;
+CREATE ROLE regress_rol_op4;
+CREATE TYPE type_op4 AS ENUM ('new', 'open', 'closed');
+CREATE FUNCTION fn_op4(int8, type_op4)
+RETURNS int8 AS $$
+    SELECT NULL::int8;
+$$ LANGUAGE sql IMMUTABLE;
+REVOKE USAGE ON TYPE type_op4 FROM regress_rol_op4;
+REVOKE USAGE ON TYPE type_op4 FROM PUBLIC;  -- Need to do this so that regress_rol_op3 is not allowed USAGE via PUBLIC
+SET ROLE regress_rol_op4;
+CREATE OPERATOR #*# (
+   leftarg = int8,
+   rightarg = type_op4,
+   procedure = fn_op4
+);
+ERROR:  permission denied for type type_op4
+ROLLBACK;
+-- Should fail. CREATE OPERATOR requires EXECUTE on function
+BEGIN TRANSACTION;
+CREATE ROLE regress_rol_op5;
+CREATE TYPE type_op5 AS ENUM ('new', 'open', 'closed');
+CREATE FUNCTION fn_op5(int8, int8)
+RETURNS int8 AS $$
+    SELECT NULL::int8;
+$$ LANGUAGE sql IMMUTABLE;
+REVOKE EXECUTE ON FUNCTION fn_op5(int8, int8) FROM regress_rol_op5;
+REVOKE EXECUTE ON FUNCTION fn_op5(int8, int8) FROM PUBLIC;-- Need to do this so that regress_rol_op3 is not allowed EXECUTE via PUBLIC
+SET ROLE regress_rol_op5;
+CREATE OPERATOR #*# (
+   leftarg = int8,
+   rightarg = int8,
+   procedure = fn_op5
+);
+ERROR:  permission denied for function fn_op5
+ROLLBACK;
+-- Should fail. CREATE OPERATOR requires USAGE on return TYPE
+BEGIN TRANSACTION;
+CREATE ROLE regress_rol_op6;
+CREATE TYPE type_op6 AS ENUM ('new', 'open', 'closed');
+CREATE FUNCTION fn_op6(int8, int8)
+RETURNS type_op6 AS $$
+    SELECT NULL::type_op6;
+$$ LANGUAGE sql IMMUTABLE;
+REVOKE USAGE ON TYPE type_op6 FROM regress_rol_op6;
+REVOKE USAGE ON TYPE type_op6 FROM PUBLIC;  -- Need to do this so that regress_rol_op3 is not allowed USAGE via PUBLIC
+SET ROLE regress_rol_op6;
+CREATE OPERATOR #*# (
+   leftarg = int8,
+   rightarg = int8,
+   procedure = fn_op6
+);
+ERROR:  permission denied for type type_op6
+ROLLBACK;
diff --git a/src/test/regress/sql/create_operator.sql b/src/test/regress/sql/create_operator.sql
index dcad804..f7a372a 100644
--- a/src/test/regress/sql/create_operator.sql
+++ b/src/test/regress/sql/create_operator.sql
@@ -34,3 +34,148 @@ CREATE OPERATOR #%# (
 
 -- Test comments
 COMMENT ON OPERATOR ###### (int4, NONE) IS 'bad right unary';
+
+-- Show deprecated message. => is deprecated now
+CREATE OPERATOR => (
+   leftarg = int8,		-- right unary
+   procedure = numeric_fac
+);
+
+-- Should fail. CREATE OPERATOR requires USAGE on SCHEMA
+BEGIN TRANSACTION;
+CREATE ROLE regress_rol_op1;
+CREATE SCHEMA schema_op1;
+GRANT USAGE ON SCHEMA schema_op1 TO PUBLIC;
+REVOKE USAGE ON SCHEMA schema_op1 FROM regress_rol_op1;
+SET ROLE regress_rol_op1;
+CREATE OPERATOR schema_op1.#*# (
+   leftarg = int8,		-- right unary
+   procedure = numeric_fac
+);
+ROLLBACK;
+
+
+-- Should fail. SETOF type functions not allowed as argument (testing leftarg)
+BEGIN TRANSACTION;
+CREATE OPERATOR #*# (
+   leftarg = SETOF int8,
+   procedure = numeric_fac
+);
+ROLLBACK;
+
+
+-- Should fail. SETOF type functions not allowed as argument (testing rightarg)
+BEGIN TRANSACTION;
+CREATE OPERATOR #*# (
+   rightarg = SETOF int8,
+   procedure = numeric_fac
+);
+ROLLBACK;
+
+
+-- Should work. Sample text-book case
+BEGIN TRANSACTION;
+CREATE OR REPLACE FUNCTION fn_op2(boolean, boolean)
+RETURNS boolean AS $$
+    SELECT NULL::BOOLEAN;
+$$ LANGUAGE sql IMMUTABLE;
+CREATE OPERATOR === (
+    LEFTARG = boolean,
+    RIGHTARG = boolean,
+    PROCEDURE = fn_op2,
+    COMMUTATOR = ===,
+    NEGATOR = !==,
+    RESTRICT = contsel,
+    JOIN = contjoinsel,
+    SORT1, SORT2, LTCMP, GTCMP, HASHES, MERGES
+);
+ROLLBACK;
+
+-- Should fail. Invalid attribute
+CREATE OPERATOR #@%# (
+   leftarg = int8,		-- right unary
+   procedure = numeric_fac,
+   invalid_att = int8
+);
+
+-- Should fail. At least leftarg or rightarg should be mandatorily specified
+CREATE OPERATOR #@%# (
+   procedure = numeric_fac
+);
+
+-- Should fail. Procedure should be mandatorily specified
+CREATE OPERATOR #@%# (
+   leftarg = int8
+);
+
+-- Should fail. CREATE OPERATOR requires USAGE on TYPE
+BEGIN TRANSACTION;
+CREATE ROLE regress_rol_op3;
+CREATE TYPE type_op3 AS ENUM ('new', 'open', 'closed');
+CREATE FUNCTION fn_op3(type_op3, int8)
+RETURNS int8 AS $$
+    SELECT NULL::int8;
+$$ LANGUAGE sql IMMUTABLE;
+REVOKE USAGE ON TYPE type_op3 FROM regress_rol_op3;
+REVOKE USAGE ON TYPE type_op3 FROM PUBLIC;  -- Need to do this so that regress_rol_op3 is not allowed USAGE via PUBLIC
+SET ROLE regress_rol_op3;
+CREATE OPERATOR #*# (
+   leftarg = type_op3,
+   rightarg = int8,
+   procedure = fn_op3
+);
+ROLLBACK;
+
+-- Should fail. CREATE OPERATOR requires USAGE on TYPE (need to check separately for rightarg)
+BEGIN TRANSACTION;
+CREATE ROLE regress_rol_op4;
+CREATE TYPE type_op4 AS ENUM ('new', 'open', 'closed');
+CREATE FUNCTION fn_op4(int8, type_op4)
+RETURNS int8 AS $$
+    SELECT NULL::int8;
+$$ LANGUAGE sql IMMUTABLE;
+REVOKE USAGE ON TYPE type_op4 FROM regress_rol_op4;
+REVOKE USAGE ON TYPE type_op4 FROM PUBLIC;  -- Need to do this so that regress_rol_op3 is not allowed USAGE via PUBLIC
+SET ROLE regress_rol_op4;
+CREATE OPERATOR #*# (
+   leftarg = int8,
+   rightarg = type_op4,
+   procedure = fn_op4
+);
+ROLLBACK;
+
+-- Should fail. CREATE OPERATOR requires EXECUTE on function
+BEGIN TRANSACTION;
+CREATE ROLE regress_rol_op5;
+CREATE TYPE type_op5 AS ENUM ('new', 'open', 'closed');
+CREATE FUNCTION fn_op5(int8, int8)
+RETURNS int8 AS $$
+    SELECT NULL::int8;
+$$ LANGUAGE sql IMMUTABLE;
+REVOKE EXECUTE ON FUNCTION fn_op5(int8, int8) FROM regress_rol_op5;
+REVOKE EXECUTE ON FUNCTION fn_op5(int8, int8) FROM PUBLIC;-- Need to do this so that regress_rol_op3 is not allowed EXECUTE via PUBLIC
+SET ROLE regress_rol_op5;
+CREATE OPERATOR #*# (
+   leftarg = int8,
+   rightarg = int8,
+   procedure = fn_op5
+);
+ROLLBACK;
+
+-- Should fail. CREATE OPERATOR requires USAGE on return TYPE
+BEGIN TRANSACTION;
+CREATE ROLE regress_rol_op6;
+CREATE TYPE type_op6 AS ENUM ('new', 'open', 'closed');
+CREATE FUNCTION fn_op6(int8, int8)
+RETURNS type_op6 AS $$
+    SELECT NULL::type_op6;
+$$ LANGUAGE sql IMMUTABLE;
+REVOKE USAGE ON TYPE type_op6 FROM regress_rol_op6;
+REVOKE USAGE ON TYPE type_op6 FROM PUBLIC;  -- Need to do this so that regress_rol_op3 is not allowed USAGE via PUBLIC
+SET ROLE regress_rol_op6;
+CREATE OPERATOR #*# (
+   leftarg = int8,
+   rightarg = int8,
+   procedure = fn_op6
+);
+ROLLBACK;