-- Hashing only works on simple equality operators "type = sametype",

-- since the hash itself depends on the bitwise representation of the type.

-- Check that allegedly hashable operators look like they might be "=".

-- NOTE: in6.5, this search finds int4eqoid andoideqint4. Until we have

-- some cleaner way of dealing with binary-equivalent types, just leave

-- thosetwo tuples in the expected output.

-- NOTE: in7.2, this search finds int4eqoid,oideqint4, and xideqint4.

--Until we havesome cleaner way of dealing with binary-equivalent types,

--just leavethosethree tuples in the expected output.

SELECT p1.oid, p1.oprname

FROM pg_operator AS p1

WHERE p1.oprcanhash AND NOT

(p1.oprkind = 'b' AND p1.oprresult = 16 AND p1.oprleft = p1.oprright AND

p1.oprname = '=' AND p1.oprcom = p1.oid);

oid | oprname

------+---------

353 | =

1136 | =

1137 | =

(2 rows)

(3 rows)

-- In 6.5 we accepted hashable array equality operators when the array element

-- type is hashable. However, what we actually need to make hashjoin work on

SELECTp1.oid,p1.oprname

FROM pg_operatorAS p1