--
-- OPR_SANITY
-- Sanity checks for common errors in making operator/procedure system tables:
-- pg_operator, pg_proc, pg_cast, pg_aggregate, pg_am,
-- pg_amop, pg_amproc, pg_opclass, pg_opfamily.
--
-- None of the SELECTs here should ever find any matching entries,
-- so the expected output is easy to maintain ;-).
-- A test failure indicates someone messed up an entry in the system tables.
--
-- NB: we assume the oidjoins test will have caught any dangling links,
-- that is OID or REGPROC fields that are not zero and do not match some
-- row in the linked-to table.  However, if we want to enforce that a link
-- field can't be 0, we have to check it here.
--
-- NB: run this test earlier than the create_operator test, because
-- that test creates some bogus operators...
-- Helper functions to deal with cases where binary-coercible matches are
-- allowed.
-- This should match IsBinaryCoercible() in parse_coerce.c.
create function binary_coercible(oid, oid) returns bool as $$
SELECT ($1 = $2) OR
 EXISTS(select 1 from pg_catalog.pg_cast where
        castsource = $1 and casttarget = $2 and
        castmethod = 'b' and castcontext = 'i') OR
 ($2 = 'pg_catalog.anyarray'::pg_catalog.regtype AND
  EXISTS(select 1 from pg_catalog.pg_type where
         oid = $1 and typelem != 0 and typlen = -1))
$$ language sql strict stable;
-- This one ignores castcontext, so it considers only physical equivalence
-- and not whether the coercion can be invoked implicitly.
create function physically_coercible(oid, oid) returns bool as $$
SELECT ($1 = $2) OR
 EXISTS(select 1 from pg_catalog.pg_cast where
        castsource = $1 and casttarget = $2 and
        castmethod = 'b') OR
 ($2 = 'pg_catalog.anyarray'::pg_catalog.regtype AND
  EXISTS(select 1 from pg_catalog.pg_type where
         oid = $1 and typelem != 0 and typlen = -1))
$$ language sql strict stable;
-- **************** pg_proc ****************
-- Look for illegal values in pg_proc fields.
SELECT p1.oid, p1.proname
FROM pg_proc as p1
WHERE p1.prolang = 0 OR p1.prorettype = 0 OR
       p1.pronargs < 0 OR
       p1.pronargdefaults < 0 OR
       p1.pronargdefaults > p1.pronargs OR
       array_lower(p1.proargtypes, 1) != 0 OR
       array_upper(p1.proargtypes, 1) != p1.pronargs-1 OR
       0::oid = ANY (p1.proargtypes) OR
       procost <= 0 OR
       CASE WHEN proretset THEN prorows <= 0 ELSE prorows != 0 END;
 oid | proname 
-----+---------
(0 rows)

-- prosrc should never be null or empty
SELECT p1.oid, p1.proname
FROM pg_proc as p1
WHERE prosrc IS NULL OR prosrc = '' OR prosrc = '-';
 oid | proname 
-----+---------
(0 rows)

-- proiswindow shouldn't be set together with proisagg or proretset
SELECT p1.oid, p1.proname
FROM pg_proc AS p1
WHERE proiswindow AND (proisagg OR proretset);
 oid | proname 
-----+---------
(0 rows)

-- pronargdefaults should be 0 iff proargdefaults is null
SELECT p1.oid, p1.proname
FROM pg_proc AS p1
WHERE (pronargdefaults <> 0) != (proargdefaults IS NOT NULL);
 oid | proname 
-----+---------
(0 rows)

-- probin should be non-empty for C functions, null everywhere else
SELECT p1.oid, p1.proname
FROM pg_proc as p1
WHERE prolang = 13 AND (probin IS NULL OR probin = '' OR probin = '-');
 oid | proname 
-----+---------
(0 rows)

SELECT p1.oid, p1.proname
FROM pg_proc as p1
WHERE prolang != 13 AND probin IS NOT NULL;
 oid | proname 
-----+---------
(0 rows)

-- Look for conflicting proc definitions (same names and input datatypes).
-- (This test should be dead code now that we have the unique index
-- pg_proc_proname_args_nsp_index, but I'll leave it in anyway.)
SELECT p1.oid, p1.proname, p2.oid, p2.proname
FROM pg_proc AS p1, pg_proc AS p2
WHERE p1.oid != p2.oid AND
    p1.proname = p2.proname AND
    p1.pronargs = p2.pronargs AND
    p1.proargtypes = p2.proargtypes;
 oid | proname | oid | proname 
-----+---------+-----+---------
(0 rows)

-- Considering only built-in procs (prolang = 12), look for multiple uses
-- of the same internal function (ie, matching prosrc fields).  It's OK to
-- have several entries with different pronames for the same internal function,
-- but conflicts in the number of arguments and other critical items should
-- be complained of.  (We don't check data types here; see next query.)
-- Note: ignore aggregate functions here, since they all point to the same
-- dummy built-in function.
SELECT p1.oid, p1.proname, p2.oid, p2.proname
FROM pg_proc AS p1, pg_proc AS p2
WHERE p1.oid < p2.oid AND
    p1.prosrc = p2.prosrc AND
    p1.prolang = 12 AND p2.prolang = 12 AND
    (p1.proisagg = false OR p2.proisagg = false) AND
    (p1.prolang != p2.prolang OR
     p1.proisagg != p2.proisagg OR
     p1.prosecdef != p2.prosecdef OR
     p1.proisstrict != p2.proisstrict OR
     p1.proretset != p2.proretset OR
     p1.provolatile != p2.provolatile OR
     p1.pronargs != p2.pronargs);
 oid | proname | oid | proname 
-----+---------+-----+---------
(0 rows)

-- Look for uses of different type OIDs in the argument/result type fields
-- for different aliases of the same built-in function.
-- This indicates that the types are being presumed to be binary-equivalent,
-- or that the built-in function is prepared to deal with different types.
-- That's not wrong, necessarily, but we make lists of all the types being
-- so treated.  Note that the expected output of this part of the test will
-- need to be modified whenever new pairs of types are made binary-equivalent,
-- or when new polymorphic built-in functions are added!
-- Note: ignore aggregate functions here, since they all point to the same
-- dummy built-in function.  Likewise, ignore range constructor functions.
SELECT DISTINCT p1.prorettype, p2.prorettype
FROM pg_proc AS p1, pg_proc AS p2
WHERE p1.oid != p2.oid AND
    p1.prosrc = p2.prosrc AND
    p1.prolang = 12 AND p2.prolang = 12 AND
    NOT p1.proisagg AND NOT p2.proisagg AND
    p1.prosrc NOT LIKE E'range\\_constructor_' AND
    p2.prosrc NOT LIKE E'range\\_constructor_' AND
    (p1.prorettype < p2.prorettype)
ORDER BY 1, 2;
 prorettype | prorettype 
------------+------------
         25 |       1043
       1114 |       1184
(2 rows)

SELECT DISTINCT p1.proargtypes[0], p2.proargtypes[0]
FROM pg_proc AS p1, pg_proc AS p2
WHERE p1.oid != p2.oid AND
    p1.prosrc = p2.prosrc AND
    p1.prolang = 12 AND p2.prolang = 12 AND
    NOT p1.proisagg AND NOT p2.proisagg AND
    p1.prosrc NOT LIKE E'range\\_constructor_' AND
    p2.prosrc NOT LIKE E'range\\_constructor_' AND
    (p1.proargtypes[0] < p2.proargtypes[0])
ORDER BY 1, 2;
 proargtypes | proargtypes 
-------------+-------------
          25 |        1042
          25 |        1043
        1114 |        1184
        1560 |        1562
        2277 |        2283
(5 rows)

SELECT DISTINCT p1.proargtypes[1], p2.proargtypes[1]
FROM pg_proc AS p1, pg_proc AS p2
WHERE p1.oid != p2.oid AND
    p1.prosrc = p2.prosrc AND
    p1.prolang = 12 AND p2.prolang = 12 AND
    NOT p1.proisagg AND NOT p2.proisagg AND
    p1.prosrc NOT LIKE E'range\\_constructor_' AND
    p2.prosrc NOT LIKE E'range\\_constructor_' AND
    (p1.proargtypes[1] < p2.proargtypes[1])
ORDER BY 1, 2;
 proargtypes | proargtypes 
-------------+-------------
          23 |          28
        1114 |        1184
        1560 |        1562
        2277 |        2283
(4 rows)

SELECT DISTINCT p1.proargtypes[2], p2.proargtypes[2]
FROM pg_proc AS p1, pg_proc AS p2
WHERE p1.oid != p2.oid AND
    p1.prosrc = p2.prosrc AND
    p1.prolang = 12 AND p2.prolang = 12 AND
    NOT p1.proisagg AND NOT p2.proisagg AND
    (p1.proargtypes[2] < p2.proargtypes[2])
ORDER BY 1, 2;
 proargtypes | proargtypes 
-------------+-------------
        1114 |        1184
(1 row)

SELECT DISTINCT p1.proargtypes[3], p2.proargtypes[3]
FROM pg_proc AS p1, pg_proc AS p2
WHERE p1.oid != p2.oid AND
    p1.prosrc = p2.prosrc AND
    p1.prolang = 12 AND p2.prolang = 12 AND
    NOT p1.proisagg AND NOT p2.proisagg AND
    (p1.proargtypes[3] < p2.proargtypes[3])
ORDER BY 1, 2;
 proargtypes | proargtypes 
-------------+-------------
        1114 |        1184
(1 row)

SELECT DISTINCT p1.proargtypes[4], p2.proargtypes[4]
FROM pg_proc AS p1, pg_proc AS p2
WHERE p1.oid != p2.oid AND
    p1.prosrc = p2.prosrc AND
    p1.prolang = 12 AND p2.prolang = 12 AND
    NOT p1.proisagg AND NOT p2.proisagg AND
    (p1.proargtypes[4] < p2.proargtypes[4])
ORDER BY 1, 2;
 proargtypes | proargtypes 
-------------+-------------
(0 rows)

SELECT DISTINCT p1.proargtypes[5], p2.proargtypes[5]
FROM pg_proc AS p1, pg_proc AS p2
WHERE p1.oid != p2.oid AND
    p1.prosrc = p2.prosrc AND
    p1.prolang = 12 AND p2.prolang = 12 AND
    NOT p1.proisagg AND NOT p2.proisagg AND
    (p1.proargtypes[5] < p2.proargtypes[5])
ORDER BY 1, 2;
 proargtypes | proargtypes 
-------------+-------------
(0 rows)

SELECT DISTINCT p1.proargtypes[6], p2.proargtypes[6]
FROM pg_proc AS p1, pg_proc AS p2
WHERE p1.oid != p2.oid AND
    p1.prosrc = p2.prosrc AND
    p1.prolang = 12 AND p2.prolang = 12 AND
    NOT p1.proisagg AND NOT p2.proisagg AND
    (p1.proargtypes[6] < p2.proargtypes[6])
ORDER BY 1, 2;
 proargtypes | proargtypes 
-------------+-------------
(0 rows)

SELECT DISTINCT p1.proargtypes[7], p2.proargtypes[7]
FROM pg_proc AS p1, pg_proc AS p2
WHERE p1.oid != p2.oid AND
    p1.prosrc = p2.prosrc AND
    p1.prolang = 12 AND p2.prolang = 12 AND
    NOT p1.proisagg AND NOT p2.proisagg AND
    (p1.proargtypes[7] < p2.proargtypes[7])
ORDER BY 1, 2;
 proargtypes | proargtypes 
-------------+-------------
(0 rows)

-- Look for functions that return type "internal" and do not have any
-- "internal" argument.  Such a function would be a security hole since
-- it might be used to call an internal function from an SQL command.
-- As of 7.3 this query should find only internal_in.
SELECT p1.oid, p1.proname
FROM pg_proc as p1
WHERE p1.prorettype = 'internal'::regtype AND NOT
    'internal'::regtype = ANY (p1.proargtypes);
 oid  |   proname   
------+-------------
 2304 | internal_in
(1 row)

-- Check for length inconsistencies between the various argument-info arrays.
SELECT p1.oid, p1.proname
FROM pg_proc as p1
WHERE proallargtypes IS NOT NULL AND
    array_length(proallargtypes,1) < array_length(proargtypes,1);
 oid | proname 
-----+---------
(0 rows)

SELECT p1.oid, p1.proname
FROM pg_proc as p1
WHERE proargmodes IS NOT NULL AND
    array_length(proargmodes,1) < array_length(proargtypes,1);
 oid | proname 
-----+---------
(0 rows)

SELECT p1.oid, p1.proname
FROM pg_proc as p1
WHERE proargnames IS NOT NULL AND
    array_length(proargnames,1) < array_length(proargtypes,1);
 oid | proname 
-----+---------
(0 rows)

SELECT p1.oid, p1.proname
FROM pg_proc as p1
WHERE proallargtypes IS NOT NULL AND proargmodes IS NOT NULL AND
    array_length(proallargtypes,1) <> array_length(proargmodes,1);
 oid | proname 
-----+---------
(0 rows)

SELECT p1.oid, p1.proname
FROM pg_proc as p1
WHERE proallargtypes IS NOT NULL AND proargnames IS NOT NULL AND
    array_length(proallargtypes,1) <> array_length(proargnames,1);
 oid | proname 
-----+---------
(0 rows)

SELECT p1.oid, p1.proname
FROM pg_proc as p1
WHERE proargmodes IS NOT NULL AND proargnames IS NOT NULL AND
    array_length(proargmodes,1) <> array_length(proargnames,1);
 oid | proname 
-----+---------
(0 rows)

-- Check for protransform functions with the wrong signature
SELECT p1.oid, p1.proname, p2.oid, p2.proname
FROM pg_proc AS p1, pg_proc AS p2
WHERE p2.oid = p1.protransform AND
    (p2.prorettype != 'internal'::regtype OR p2.proretset OR p2.pronargs != 1
     OR p2.proargtypes[0] != 'internal'::regtype);
 oid | proname | oid | proname 
-----+---------+-----+---------
(0 rows)

-- Insist that all built-in pg_proc entries have descriptions
SELECT p1.oid, p1.proname
FROM pg_proc as p1 LEFT JOIN pg_description as d
     ON p1.tableoid = d.classoid and p1.oid = d.objoid and d.objsubid = 0
WHERE d.classoid IS NULL AND p1.oid <= 9999;
 oid | proname 
-----+---------
(0 rows)

-- **************** pg_cast ****************
-- Catch bogus values in pg_cast columns (other than cases detected by
-- oidjoins test).
SELECT *
FROM pg_cast c
WHERE castsource = 0 OR casttarget = 0 OR castcontext NOT IN ('e', 'a', 'i')
    OR castmethod NOT IN ('f', 'b' ,'i');
 castsource | casttarget | castfunc | castcontext | castmethod 
------------+------------+----------+-------------+------------
(0 rows)

-- Check that castfunc is nonzero only for cast methods that need a function,
-- and zero otherwise
SELECT *
FROM pg_cast c
WHERE (castmethod = 'f' AND castfunc = 0)
   OR (castmethod IN ('b', 'i') AND castfunc <> 0);
 castsource | casttarget | castfunc | castcontext | castmethod 
------------+------------+----------+-------------+------------
(0 rows)

-- Look for casts to/from the same type that aren't length coercion functions.
-- (We assume they are length coercions if they take multiple arguments.)
-- Such entries are not necessarily harmful, but they are useless.
SELECT *
FROM pg_cast c
WHERE castsource = casttarget AND castfunc = 0;
 castsource | casttarget | castfunc | castcontext | castmethod 
------------+------------+----------+-------------+------------
(0 rows)

SELECT c.*
FROM pg_cast c, pg_proc p
WHERE c.castfunc = p.oid AND p.pronargs < 2 AND castsource = casttarget;
 castsource | casttarget | castfunc | castcontext | castmethod 
------------+------------+----------+-------------+------------
(0 rows)

-- Look for cast functions that don't have the right signature.  The
-- argument and result types in pg_proc must be the same as, or binary
-- compatible with, what it says in pg_cast.
-- As a special case, we allow casts from CHAR(n) that use functions
-- declared to take TEXT.  This does not pass the binary-coercibility test
-- because CHAR(n)-to-TEXT normally invokes rtrim().  However, the results
-- are the same, so long as the function is one that ignores trailing blanks.
SELECT c.*
FROM pg_cast c, pg_proc p
WHERE c.castfunc = p.oid AND
    (p.pronargs < 1 OR p.pronargs > 3
     OR NOT (binary_coercible(c.castsource, p.proargtypes[0])
             OR (c.castsource = 'character'::regtype AND
                 p.proargtypes[0] = 'text'::regtype))
     OR NOT binary_coercible(p.prorettype, c.casttarget));
 castsource | casttarget | castfunc | castcontext | castmethod 
------------+------------+----------+-------------+------------
(0 rows)

SELECT c.*
FROM pg_cast c, pg_proc p
WHERE c.castfunc = p.oid AND
    ((p.pronargs > 1 AND p.proargtypes[1] != 'int4'::regtype) OR
     (p.pronargs > 2 AND p.proargtypes[2] != 'bool'::regtype));
 castsource | casttarget | castfunc | castcontext | castmethod 
------------+------------+----------+-------------+------------
(0 rows)

-- Look for binary compatible casts that do not have the reverse
-- direction registered as well, or where the reverse direction is not
-- also binary compatible.  This is legal, but usually not intended.
-- As of 7.4, this finds the casts from text and varchar to bpchar, because
-- those are binary-compatible while the reverse way goes through rtrim().
-- As of 8.2, this finds the cast from cidr to inet, because that is a
-- trivial binary coercion while the other way goes through inet_to_cidr().
-- As of 8.3, this finds the casts from xml to text, varchar, and bpchar,
-- because those are binary-compatible while the reverse goes through
-- texttoxml(), which does an XML syntax check.
-- As of 9.1, this finds the cast from pg_node_tree to text, which we
-- intentionally do not provide a reverse pathway for.
SELECT castsource::regtype, casttarget::regtype, castfunc, castcontext
FROM pg_cast c
WHERE c.castmethod = 'b' AND
    NOT EXISTS (SELECT 1 FROM pg_cast k
                WHERE k.castmethod = 'b' AND
                    k.castsource = c.casttarget AND
                    k.casttarget = c.castsource);
    castsource     |    casttarget     | castfunc | castcontext 
-------------------+-------------------+----------+-------------
 text              | character         |        0 | i
 character varying | character         |        0 | i
 pg_node_tree      | text              |        0 | i
 cidr              | inet              |        0 | i
 xml               | text              |        0 | a
 xml               | character varying |        0 | a
 xml               | character         |        0 | a
(7 rows)

-- **************** pg_operator ****************
-- Look for illegal values in pg_operator fields.
SELECT p1.oid, p1.oprname
FROM pg_operator as p1
WHERE (p1.oprkind != 'b' AND p1.oprkind != 'l' AND p1.oprkind != 'r') OR
    p1.oprresult = 0 OR p1.oprcode = 0;
 oid | oprname 
-----+---------
(0 rows)

-- Look for missing or unwanted operand types
SELECT p1.oid, p1.oprname
FROM pg_operator as p1
WHERE (p1.oprleft = 0 and p1.oprkind != 'l') OR
    (p1.oprleft != 0 and p1.oprkind = 'l') OR
    (p1.oprright = 0 and p1.oprkind != 'r') OR
    (p1.oprright != 0 and p1.oprkind = 'r');
 oid | oprname 
-----+---------
(0 rows)

-- Look for conflicting operator definitions (same names and input datatypes).
SELECT p1.oid, p1.oprcode, p2.oid, p2.oprcode
FROM pg_operator AS p1, pg_operator AS p2
WHERE p1.oid != p2.oid AND
    p1.oprname = p2.oprname AND
    p1.oprkind = p2.oprkind AND
    p1.oprleft = p2.oprleft AND
    p1.oprright = p2.oprright;
 oid | oprcode | oid | oprcode 
-----+---------+-----+---------
(0 rows)

-- Look for commutative operators that don't commute.
-- DEFINITIONAL NOTE: If A.oprcom = B, then x A y has the same result as y B x.
-- We expect that B will always say that B.oprcom = A as well; that's not
-- inherently essential, but it would be inefficient not to mark it so.
SELECT p1.oid, p1.oprcode, p2.oid, p2.oprcode
FROM pg_operator AS p1, pg_operator AS p2
WHERE p1.oprcom = p2.oid AND
    (p1.oprkind != 'b' OR
     p1.oprleft != p2.oprright OR
     p1.oprright != p2.oprleft OR
     p1.oprresult != p2.oprresult OR
     p1.oid != p2.oprcom);
 oid | oprcode | oid | oprcode 
-----+---------+-----+---------
(0 rows)

-- Look for negatory operators that don't agree.
-- DEFINITIONAL NOTE: If A.oprnegate = B, then both A and B must yield
-- boolean results, and (x A y) == ! (x B y), or the equivalent for
-- single-operand operators.
-- We expect that B will always say that B.oprnegate = A as well; that's not
-- inherently essential, but it would be inefficient not to mark it so.
-- Also, A and B had better not be the same operator.
SELECT p1.oid, p1.oprcode, p2.oid, p2.oprcode
FROM pg_operator AS p1, pg_operator AS p2
WHERE p1.oprnegate = p2.oid AND
    (p1.oprkind != p2.oprkind OR
     p1.oprleft != p2.oprleft OR
     p1.oprright != p2.oprright OR
     p1.oprresult != 'bool'::regtype OR
     p2.oprresult != 'bool'::regtype OR
     p1.oid != p2.oprnegate OR
     p1.oid = p2.oid);
 oid | oprcode | oid | oprcode 
-----+---------+-----+---------
(0 rows)

-- A mergejoinable or hashjoinable operator must be binary, must return
-- boolean, and must have a commutator (itself, unless it's a cross-type
-- operator).
SELECT p1.oid, p1.oprname FROM pg_operator AS p1
WHERE (p1.oprcanmerge OR p1.oprcanhash) AND NOT
    (p1.oprkind = 'b' AND p1.oprresult = 'bool'::regtype AND p1.oprcom != 0);
 oid | oprname 
-----+---------
(0 rows)

-- What's more, the commutator had better be mergejoinable/hashjoinable too.
SELECT p1.oid, p1.oprname, p2.oid, p2.oprname
FROM pg_operator AS p1, pg_operator AS p2
WHERE p1.oprcom = p2.oid AND
    (p1.oprcanmerge != p2.oprcanmerge OR
     p1.oprcanhash != p2.oprcanhash);
 oid | oprname | oid | oprname 
-----+---------+-----+---------
(0 rows)

-- Mergejoinable operators should appear as equality members of btree index
-- opfamilies.
SELECT p1.oid, p1.oprname
FROM pg_operator AS p1
WHERE p1.oprcanmerge AND NOT EXISTS
  (SELECT 1 FROM pg_amop
   WHERE amopmethod = (SELECT oid FROM pg_am WHERE amname = 'btree') AND
         amopopr = p1.oid AND amopstrategy = 3);
 oid | oprname 
-----+---------
(0 rows)

-- And the converse.
SELECT p1.oid, p1.oprname, p.amopfamily
FROM pg_operator AS p1, pg_amop p
WHERE amopopr = p1.oid
  AND amopmethod = (SELECT oid FROM pg_am WHERE amname = 'btree')
  AND amopstrategy = 3
  AND NOT p1.oprcanmerge;
 oid | oprname | amopfamily 
-----+---------+------------
(0 rows)

-- Hashable operators should appear as members of hash index opfamilies.
SELECT p1.oid, p1.oprname
FROM pg_operator AS p1
WHERE p1.oprcanhash AND NOT EXISTS
  (SELECT 1 FROM pg_amop
   WHERE amopmethod = (SELECT oid FROM pg_am WHERE amname = 'hash') AND
         amopopr = p1.oid AND amopstrategy = 1);
 oid | oprname 
-----+---------
(0 rows)

-- And the converse.
SELECT p1.oid, p1.oprname, p.amopfamily
FROM pg_operator AS p1, pg_amop p
WHERE amopopr = p1.oid
  AND amopmethod = (SELECT oid FROM pg_am WHERE amname = 'hash')
  AND NOT p1.oprcanhash;
 oid | oprname | amopfamily 
-----+---------+------------
(0 rows)

-- Check that each operator defined in pg_operator matches its oprcode entry
-- in pg_proc.  Easiest to do this separately for each oprkind.
SELECT p1.oid, p1.oprname, p2.oid, p2.proname
FROM pg_operator AS p1, pg_proc AS p2
WHERE p1.oprcode = p2.oid AND
    p1.oprkind = 'b' AND
    (p2.pronargs != 2
     OR NOT binary_coercible(p2.prorettype, p1.oprresult)
     OR NOT binary_coercible(p1.oprleft, p2.proargtypes[0])
     OR NOT binary_coercible(p1.oprright, p2.proargtypes[1]));
 oid | oprname | oid | proname 
-----+---------+-----+---------
(0 rows)

SELECT p1.oid, p1.oprname, p2.oid, p2.proname
FROM pg_operator AS p1, pg_proc AS p2
WHERE p1.oprcode = p2.oid AND
    p1.oprkind = 'l' AND
    (p2.pronargs != 1
     OR NOT binary_coercible(p2.prorettype, p1.oprresult)
     OR NOT binary_coercible(p1.oprright, p2.proargtypes[0])
     OR p1.oprleft != 0);
 oid | oprname | oid | proname 
-----+---------+-----+---------
(0 rows)

SELECT p1.oid, p1.oprname, p2.oid, p2.proname
FROM pg_operator AS p1, pg_proc AS p2
WHERE p1.oprcode = p2.oid AND
    p1.oprkind = 'r' AND
    (p2.pronargs != 1
     OR NOT binary_coercible(p2.prorettype, p1.oprresult)
     OR NOT binary_coercible(p1.oprleft, p2.proargtypes[0])
     OR p1.oprright != 0);
 oid | oprname | oid | proname 
-----+---------+-----+---------
(0 rows)

-- If the operator is mergejoinable or hashjoinable, its underlying function
-- should not be volatile.
SELECT p1.oid, p1.oprname, p2.oid, p2.proname
FROM pg_operator AS p1, pg_proc AS p2
WHERE p1.oprcode = p2.oid AND
    (p1.oprcanmerge OR p1.oprcanhash) AND
    p2.provolatile = 'v';
 oid | oprname | oid | proname 
-----+---------+-----+---------
(0 rows)

-- If oprrest is set, the operator must return boolean,
-- and it must link to a proc with the right signature
-- to be a restriction selectivity estimator.
-- The proc signature we want is: float8 proc(internal, oid, internal, int4)
SELECT p1.oid, p1.oprname, p2.oid, p2.proname
FROM pg_operator AS p1, pg_proc AS p2
WHERE p1.oprrest = p2.oid AND
    (p1.oprresult != 'bool'::regtype OR
     p2.prorettype != 'float8'::regtype OR p2.proretset OR
     p2.pronargs != 4 OR
     p2.proargtypes[0] != 'internal'::regtype OR
     p2.proargtypes[1] != 'oid'::regtype OR
     p2.proargtypes[2] != 'internal'::regtype OR
     p2.proargtypes[3] != 'int4'::regtype);
 oid | oprname | oid | proname 
-----+---------+-----+---------
(0 rows)

-- If oprjoin is set, the operator must be a binary boolean op,
-- and it must link to a proc with the right signature
-- to be a join selectivity estimator.
-- The proc signature we want is: float8 proc(internal, oid, internal, int2, internal)
-- (Note: the old signature with only 4 args is still allowed, but no core
-- estimator should be using it.)
SELECT p1.oid, p1.oprname, p2.oid, p2.proname
FROM pg_operator AS p1, pg_proc AS p2
WHERE p1.oprjoin = p2.oid AND
    (p1.oprkind != 'b' OR p1.oprresult != 'bool'::regtype OR
     p2.prorettype != 'float8'::regtype OR p2.proretset OR
     p2.pronargs != 5 OR
     p2.proargtypes[0] != 'internal'::regtype OR
     p2.proargtypes[1] != 'oid'::regtype OR
     p2.proargtypes[2] != 'internal'::regtype OR
     p2.proargtypes[3] != 'int2'::regtype OR
     p2.proargtypes[4] != 'internal'::regtype);
 oid | oprname | oid | proname 
-----+---------+-----+---------
(0 rows)

-- Insist that all built-in pg_operator entries have descriptions
SELECT p1.oid, p1.oprname
FROM pg_operator as p1 LEFT JOIN pg_description as d
     ON p1.tableoid = d.classoid and p1.oid = d.objoid and d.objsubid = 0
WHERE d.classoid IS NULL AND p1.oid <= 9999;
 oid | oprname 
-----+---------
(0 rows)

-- Check that operators' underlying functions have suitable comments,
-- namely 'implementation of XXX operator'.  In some cases involving legacy
-- names for operators, there are multiple operators referencing the same
-- pg_proc entry, so ignore operators whose comments say they are deprecated.
-- We also have a few functions that are both operator support and meant to
-- be called directly; those should have comments matching their operator.
WITH funcdescs AS (
  SELECT p.oid as p_oid, proname, o.oid as o_oid,
    obj_description(p.oid, 'pg_proc') as prodesc,
    'implementation of ' || oprname || ' operator' as expecteddesc,
    obj_description(o.oid, 'pg_operator') as oprdesc
  FROM pg_proc p JOIN pg_operator o ON oprcode = p.oid
  WHERE o.oid <= 9999
)
SELECT * FROM funcdescs
  WHERE prodesc IS DISTINCT FROM expecteddesc
    AND oprdesc NOT LIKE 'deprecated%'
    AND prodesc IS DISTINCT FROM oprdesc;
 p_oid | proname | o_oid | prodesc | expecteddesc | oprdesc 
-------+---------+-------+---------+--------------+---------
(0 rows)

-- **************** pg_aggregate ****************
-- Look for illegal values in pg_aggregate fields.
SELECT ctid, aggfnoid::oid
FROM pg_aggregate as p1
WHERE aggfnoid = 0 OR aggtransfn = 0 OR aggtranstype = 0;
 ctid | aggfnoid 
------+----------
(0 rows)

-- Make sure the matching pg_proc entry is sensible, too.
SELECT a.aggfnoid::oid, p.proname
FROM pg_aggregate as a, pg_proc as p
WHERE a.aggfnoid = p.oid AND
    (NOT p.proisagg OR p.proretset);
 aggfnoid | proname 
----------+---------
(0 rows)

-- Make sure there are no proisagg pg_proc entries without matches.
SELECT oid, proname
FROM pg_proc as p
WHERE p.proisagg AND
    NOT EXISTS (SELECT 1 FROM pg_aggregate a WHERE a.aggfnoid = p.oid);
 oid | proname 
-----+---------
(0 rows)

-- If there is no finalfn then the output type must be the transtype.
SELECT a.aggfnoid::oid, p.proname
FROM pg_aggregate as a, pg_proc as p
WHERE a.aggfnoid = p.oid AND
    a.aggfinalfn = 0 AND p.prorettype != a.aggtranstype;
 aggfnoid | proname 
----------+---------
(0 rows)

-- Cross-check transfn against its entry in pg_proc.
-- NOTE: use physically_coercible here, not binary_coercible, because
-- max and min on abstime are implemented using int4larger/int4smaller.
SELECT a.aggfnoid::oid, p.proname, ptr.oid, ptr.proname
FROM pg_aggregate AS a, pg_proc AS p, pg_proc AS ptr
WHERE a.aggfnoid = p.oid AND
    a.aggtransfn = ptr.oid AND
    (ptr.proretset
     OR NOT (ptr.pronargs = p.pronargs + 1)
     OR NOT physically_coercible(ptr.prorettype, a.aggtranstype)
     OR NOT physically_coercible(a.aggtranstype, ptr.proargtypes[0])
     OR (p.pronargs > 0 AND
         NOT physically_coercible(p.proargtypes[0], ptr.proargtypes[1]))
     OR (p.pronargs > 1 AND
         NOT physically_coercible(p.proargtypes[1], ptr.proargtypes[2]))
     OR (p.pronargs > 2 AND
         NOT physically_coercible(p.proargtypes[2], ptr.proargtypes[3]))
     -- we could carry the check further, but that's enough for now
    );
 aggfnoid | proname | oid | proname 
----------+---------+-----+---------
(0 rows)

-- Cross-check finalfn (if present) against its entry in pg_proc.
SELECT a.aggfnoid::oid, p.proname, pfn.oid, pfn.proname
FROM pg_aggregate AS a, pg_proc AS p, pg_proc AS pfn
WHERE a.aggfnoid = p.oid AND
    a.aggfinalfn = pfn.oid AND
    (pfn.proretset
     OR NOT binary_coercible(pfn.prorettype, p.prorettype)
     OR pfn.pronargs != 1
     OR NOT binary_coercible(a.aggtranstype, pfn.proargtypes[0]));
 aggfnoid | proname | oid | proname 
----------+---------+-----+---------
(0 rows)

-- If transfn is strict then either initval should be non-NULL, or
-- input type should match transtype so that the first non-null input
-- can be assigned as the state value.
SELECT a.aggfnoid::oid, p.proname, ptr.oid, ptr.proname
FROM pg_aggregate AS a, pg_proc AS p, pg_proc AS ptr
WHERE a.aggfnoid = p.oid AND
    a.aggtransfn = ptr.oid AND ptr.proisstrict AND
    a.agginitval IS NULL AND
    NOT binary_coercible(p.proargtypes[0], a.aggtranstype);
 aggfnoid | proname | oid | proname 
----------+---------+-----+---------
(0 rows)

-- Cross-check aggsortop (if present) against pg_operator.
-- We expect to find entries for bool_and, bool_or, every, max, and min.
SELECT DISTINCT proname, oprname
FROM pg_operator AS o, pg_aggregate AS a, pg_proc AS p
WHERE a.aggfnoid = p.oid AND a.aggsortop = o.oid
ORDER BY 1, 2;
 proname  | oprname 
----------+---------
 bool_and | <
 bool_or  | >
 every    | <
 max      | >
 min      | <
(5 rows)

-- Check datatypes match
SELECT a.aggfnoid::oid, o.oid
FROM pg_operator AS o, pg_aggregate AS a, pg_proc AS p
WHERE a.aggfnoid = p.oid AND a.aggsortop = o.oid AND
    (oprkind != 'b' OR oprresult != 'boolean'::regtype
     OR oprleft != p.proargtypes[0] OR oprright != p.proargtypes[0]);
 aggfnoid | oid 
----------+-----
(0 rows)

-- Check operator is a suitable btree opfamily member
SELECT a.aggfnoid::oid, o.oid
FROM pg_operator AS o, pg_aggregate AS a, pg_proc AS p
WHERE a.aggfnoid = p.oid AND a.aggsortop = o.oid AND
    NOT EXISTS(SELECT 1 FROM pg_amop
               WHERE amopmethod = (SELECT oid FROM pg_am WHERE amname = 'btree')
                     AND amopopr = o.oid
                     AND amoplefttype = o.oprleft
                     AND amoprighttype = o.oprright);
 aggfnoid | oid 
----------+-----
(0 rows)

-- Check correspondence of btree strategies and names
SELECT DISTINCT proname, oprname, amopstrategy
FROM pg_operator AS o, pg_aggregate AS a, pg_proc AS p,
     pg_amop as ao
WHERE a.aggfnoid = p.oid AND a.aggsortop = o.oid AND
    amopopr = o.oid AND
    amopmethod = (SELECT oid FROM pg_am WHERE amname = 'btree')
ORDER BY 1, 2;
 proname  | oprname | amopstrategy 
----------+---------+--------------
 bool_and | <       |            1
 bool_or  | >       |            5
 every    | <       |            1
 max      | >       |            5
 min      | <       |            1
(5 rows)

-- Check that there are not aggregates with the same name and different
-- numbers of arguments.  While not technically wrong, we have a project policy
-- to avoid this because it opens the door for confusion in connection with
-- ORDER BY: novices frequently put the ORDER BY in the wrong place.
-- See the fate of the single-argument form of string_agg() for history.
-- The only aggregates that should show up here are count(x) and count(*).
SELECT p1.oid::regprocedure, p2.oid::regprocedure
FROM pg_proc AS p1, pg_proc AS p2
WHERE p1.oid < p2.oid AND p1.proname = p2.proname AND
    p1.proisagg AND p2.proisagg AND
    array_dims(p1.proargtypes) != array_dims(p2.proargtypes)
ORDER BY 1;
     oid      |   oid   
--------------+---------
 count("any") | count()
(1 row)

-- For the same reason, aggregates with default arguments are no good.
SELECT oid, proname
FROM pg_proc AS p
WHERE proisagg AND proargdefaults IS NOT NULL;
 oid | proname 
-----+---------
(0 rows)

-- **************** pg_opfamily ****************
-- Look for illegal values in pg_opfamily fields
SELECT p1.oid
FROM pg_opfamily as p1
WHERE p1.opfmethod = 0 OR p1.opfnamespace = 0;
 oid 
-----
(0 rows)

-- **************** pg_opclass ****************
-- Look for illegal values in pg_opclass fields
SELECT p1.oid
FROM pg_opclass AS p1
WHERE p1.opcmethod = 0 OR p1.opcnamespace = 0 OR p1.opcfamily = 0
    OR p1.opcintype = 0;
 oid 
-----
(0 rows)

-- opcmethod must match owning opfamily's opfmethod
SELECT p1.oid, p2.oid
FROM pg_opclass AS p1, pg_opfamily AS p2
WHERE p1.opcfamily = p2.oid AND p1.opcmethod != p2.opfmethod;
 oid | oid 
-----+-----
(0 rows)

-- There should not be multiple entries in pg_opclass with opcdefault true
-- and the same opcmethod/opcintype combination.
SELECT p1.oid, p2.oid
FROM pg_opclass AS p1, pg_opclass AS p2
WHERE p1.oid != p2.oid AND
    p1.opcmethod = p2.opcmethod AND p1.opcintype = p2.opcintype AND
    p1.opcdefault AND p2.opcdefault;
 oid | oid 
-----+-----
(0 rows)

-- **************** pg_amop ****************
-- Look for illegal values in pg_amop fields
SELECT p1.amopfamily, p1.amopstrategy
FROM pg_amop as p1
WHERE p1.amopfamily = 0 OR p1.amoplefttype = 0 OR p1.amoprighttype = 0
    OR p1.amopopr = 0 OR p1.amopmethod = 0 OR p1.amopstrategy < 1;
 amopfamily | amopstrategy 
------------+--------------
(0 rows)

SELECT p1.amopfamily, p1.amopstrategy
FROM pg_amop as p1
WHERE NOT ((p1.amoppurpose = 's' AND p1.amopsortfamily = 0) OR
           (p1.amoppurpose = 'o' AND p1.amopsortfamily <> 0));
 amopfamily | amopstrategy 
------------+--------------
(0 rows)

-- amoplefttype/amoprighttype must match the operator
SELECT p1.oid, p2.oid
FROM pg_amop AS p1, pg_operator AS p2
WHERE p1.amopopr = p2.oid AND NOT
    (p1.amoplefttype = p2.oprleft AND p1.amoprighttype = p2.oprright);
 oid | oid 
-----+-----
(0 rows)

-- amopmethod must match owning opfamily's opfmethod
SELECT p1.oid, p2.oid
FROM pg_amop AS p1, pg_opfamily AS p2
WHERE p1.amopfamily = p2.oid AND p1.amopmethod != p2.opfmethod;
 oid | oid 
-----+-----
(0 rows)

-- amopsortfamily, if present, must reference a btree family
SELECT p1.amopfamily, p1.amopstrategy
FROM pg_amop AS p1
WHERE p1.amopsortfamily <> 0 AND NOT EXISTS
    (SELECT 1 from pg_opfamily op WHERE op.oid = p1.amopsortfamily
     AND op.opfmethod = (SELECT oid FROM pg_am WHERE amname = 'btree'));
 amopfamily | amopstrategy 
------------+--------------
(0 rows)

-- check for ordering operators not supported by parent AM
SELECT p1.amopfamily, p1.amopopr, p2.oid, p2.amname
FROM pg_amop AS p1, pg_am AS p2
WHERE p1.amopmethod = p2.oid AND
    p1.amoppurpose = 'o' AND NOT p2.amcanorderbyop;
 amopfamily | amopopr | oid | amname 
------------+---------+-----+--------
(0 rows)

-- Cross-check amopstrategy index against parent AM
SELECT p1.amopfamily, p1.amopopr, p2.oid, p2.amname
FROM pg_amop AS p1, pg_am AS p2
WHERE p1.amopmethod = p2.oid AND
    p1.amopstrategy > p2.amstrategies AND p2.amstrategies <> 0;
 amopfamily | amopopr | oid | amname 
------------+---------+-----+--------
(0 rows)

-- Detect missing pg_amop entries: should have as many strategy operators
-- as AM expects for each datatype combination supported by the opfamily.
-- We can't check this for AMs with variable strategy sets.
SELECT p1.amname, p2.amoplefttype, p2.amoprighttype
FROM pg_am AS p1, pg_amop AS p2
WHERE p2.amopmethod = p1.oid AND
    p1.amstrategies <> 0 AND
    p1.amstrategies != (SELECT count(*) FROM pg_amop AS p3
                        WHERE p3.amopfamily = p2.amopfamily AND
                              p3.amoplefttype = p2.amoplefttype AND
                              p3.amoprighttype = p2.amoprighttype AND
                              p3.amoppurpose = 's');
 amname | amoplefttype | amoprighttype 
--------+--------------+---------------
(0 rows)

-- Currently, none of the AMs with fixed strategy sets support ordering ops.
SELECT p1.amname, p2.amopfamily, p2.amopstrategy
FROM pg_am AS p1, pg_amop AS p2
WHERE p2.amopmethod = p1.oid AND
    p1.amstrategies <> 0 AND p2.amoppurpose <> 's';
 amname | amopfamily | amopstrategy 
--------+------------+--------------
(0 rows)

-- Check that amopopr points at a reasonable-looking operator, ie a binary
-- operator.  If it's a search operator it had better yield boolean,
-- otherwise an input type of its sort opfamily.
SELECT p1.amopfamily, p1.amopopr, p2.oid, p2.oprname
FROM pg_amop AS p1, pg_operator AS p2
WHERE p1.amopopr = p2.oid AND
    p2.oprkind != 'b';
 amopfamily | amopopr | oid | oprname 
------------+---------+-----+---------
(0 rows)

SELECT p1.amopfamily, p1.amopopr, p2.oid, p2.oprname
FROM pg_amop AS p1, pg_operator AS p2
WHERE p1.amopopr = p2.oid AND p1.amoppurpose = 's' AND
    p2.oprresult != 'bool'::regtype;
 amopfamily | amopopr | oid | oprname 
------------+---------+-----+---------
(0 rows)

SELECT p1.amopfamily, p1.amopopr, p2.oid, p2.oprname
FROM pg_amop AS p1, pg_operator AS p2
WHERE p1.amopopr = p2.oid AND p1.amoppurpose = 'o' AND NOT EXISTS
    (SELECT 1 FROM pg_opclass op
     WHERE opcfamily = p1.amopsortfamily AND opcintype = p2.oprresult);
 amopfamily | amopopr | oid | oprname 
------------+---------+-----+---------
(0 rows)

-- Make a list of all the distinct operator names being used in particular
-- strategy slots.  This is a bit hokey, since the list might need to change
-- in future releases, but it's an effective way of spotting mistakes such as
-- swapping two operators within a family.
SELECT DISTINCT amopmethod, amopstrategy, oprname
FROM pg_amop p1 LEFT JOIN pg_operator p2 ON amopopr = p2.oid
ORDER BY 1, 2, 3;
 amopmethod | amopstrategy | oprname 
------------+--------------+---------
        403 |            1 | <
        403 |            1 | ~<~
        403 |            2 | <=
        403 |            2 | ~<=~
        403 |            3 | =
        403 |            4 | >=
        403 |            4 | ~>=~
        403 |            5 | >
        403 |            5 | ~>~
        405 |            1 | =
        783 |            1 | <<
        783 |            1 | @@
        783 |            2 | &<
        783 |            3 | &&
        783 |            4 | &>
        783 |            5 | >>
        783 |            6 | -|-
        783 |            6 | ~=
        783 |            7 | @>
        783 |            8 | <@
        783 |            9 | &<|
        783 |           10 | <<|
        783 |           10 | <^
        783 |           11 | >^
        783 |           11 | |>>
        783 |           12 | |&>
        783 |           13 | ~
        783 |           14 | @
        783 |           15 | <->
        783 |           16 | @>
        783 |           18 | =
        783 |           28 | <@
        783 |           48 | <@
        783 |           68 | <@
       2742 |            1 | &&
       2742 |            1 | @@
       2742 |            2 | @>
       2742 |            2 | @@@
       2742 |            3 | <@
       2742 |            4 | =
       4000 |            1 | <<
       4000 |            1 | ~<~
       4000 |            2 | &<
       4000 |            2 | ~<=~
       4000 |            3 | &&
       4000 |            3 | =
       4000 |            4 | &>
       4000 |            4 | ~>=~
       4000 |            5 | >>
       4000 |            5 | ~>~
       4000 |            6 | -|-
       4000 |            6 | ~=
       4000 |            7 | @>
       4000 |            8 | <@
       4000 |           10 | <^
       4000 |           11 | <
       4000 |           11 | >^
       4000 |           12 | <=
       4000 |           14 | >=
       4000 |           15 | >
       4000 |           16 | @>
       4000 |           18 | =
(62 rows)

-- Check that all opclass search operators have selectivity estimators.
-- This is not absolutely required, but it seems a reasonable thing
-- to insist on for all standard datatypes.
SELECT p1.amopfamily, p1.amopopr, p2.oid, p2.oprname
FROM pg_amop AS p1, pg_operator AS p2
WHERE p1.amopopr = p2.oid AND p1.amoppurpose = 's' AND
    (p2.oprrest = 0 OR p2.oprjoin = 0);
 amopfamily | amopopr | oid | oprname 
------------+---------+-----+---------
(0 rows)

-- Check that each opclass in an opfamily has associated operators, that is
-- ones whose oprleft matches opcintype (possibly by coercion).
SELECT p1.opcname, p1.opcfamily
FROM pg_opclass AS p1
WHERE NOT EXISTS(SELECT 1 FROM pg_amop AS p2
                 WHERE p2.amopfamily = p1.opcfamily
                   AND binary_coercible(p1.opcintype, p2.amoplefttype));
 opcname | opcfamily 
---------+-----------
(0 rows)

-- Check that each operator listed in pg_amop has an associated opclass,
-- that is one whose opcintype matches oprleft (possibly by coercion).
-- Otherwise the operator is useless because it cannot be matched to an index.
-- (In principle it could be useful to list such operators in multiple-datatype
-- btree opfamilies, but in practice you'd expect there to be an opclass for
-- every datatype the family knows about.)
SELECT p1.amopfamily, p1.amopstrategy, p1.amopopr
FROM pg_amop AS p1
WHERE NOT EXISTS(SELECT 1 FROM pg_opclass AS p2
                 WHERE p2.opcfamily = p1.amopfamily
                   AND binary_coercible(p2.opcintype, p1.amoplefttype));
 amopfamily | amopstrategy | amopopr 
------------+--------------+---------
(0 rows)

-- Operators that are primary members of opclasses must be immutable (else
-- it suggests that the index ordering isn't fixed).  Operators that are
-- cross-type members need only be stable, since they are just shorthands
-- for index probe queries.
SELECT p1.amopfamily, p1.amopopr, p2.oprname, p3.prosrc
FROM pg_amop AS p1, pg_operator AS p2, pg_proc AS p3
WHERE p1.amopopr = p2.oid AND p2.oprcode = p3.oid AND
    p1.amoplefttype = p1.amoprighttype AND
    p3.provolatile != 'i';
 amopfamily | amopopr | oprname | prosrc 
------------+---------+---------+--------
(0 rows)

SELECT p1.amopfamily, p1.amopopr, p2.oprname, p3.prosrc
FROM pg_amop AS p1, pg_operator AS p2, pg_proc AS p3
WHERE p1.amopopr = p2.oid AND p2.oprcode = p3.oid AND
    p1.amoplefttype != p1.amoprighttype AND
    p3.provolatile = 'v';
 amopfamily | amopopr | oprname | prosrc 
------------+---------+---------+--------
(0 rows)

-- Multiple-datatype btree opfamilies should provide closed sets of equality
-- operators; that is if you provide int2 = int4 and int4 = int8 then you
-- should also provide int2 = int8 (and commutators of all these).  This is
-- important because the planner tries to deduce additional qual clauses from
-- transitivity of mergejoinable operators.  If there are clauses
-- int2var = int4var and int4var = int8var, the planner will want to deduce
-- int2var = int8var ... so there should be a way to represent that.  While
-- a missing cross-type operator is now only an efficiency loss rather than
-- an error condition, it still seems reasonable to insist that all built-in
-- opfamilies be complete.
-- check commutative closure
SELECT p1.amoplefttype, p1.amoprighttype
FROM pg_amop AS p1
WHERE p1.amopmethod = (SELECT oid FROM pg_am WHERE amname = 'btree') AND
    p1.amopstrategy = 3 AND
    p1.amoplefttype != p1.amoprighttype AND
    NOT EXISTS(SELECT 1 FROM pg_amop p2 WHERE
                 p2.amopfamily = p1.amopfamily AND
                 p2.amoplefttype = p1.amoprighttype AND
                 p2.amoprighttype = p1.amoplefttype AND
                 p2.amopstrategy = 3);
 amoplefttype | amoprighttype 
--------------+---------------
(0 rows)

-- check transitive closure
SELECT p1.amoplefttype, p1.amoprighttype, p2.amoprighttype
FROM pg_amop AS p1, pg_amop AS p2
WHERE p1.amopfamily = p2.amopfamily AND
    p1.amoprighttype = p2.amoplefttype AND
    p1.amopmethod = (SELECT oid FROM pg_am WHERE amname = 'btree') AND
    p2.amopmethod = (SELECT oid FROM pg_am WHERE amname = 'btree') AND
    p1.amopstrategy = 3 AND p2.amopstrategy = 3 AND
    p1.amoplefttype != p1.amoprighttype AND
    p2.amoplefttype != p2.amoprighttype AND
    NOT EXISTS(SELECT 1 FROM pg_amop p3 WHERE
                 p3.amopfamily = p1.amopfamily AND
                 p3.amoplefttype = p1.amoplefttype AND
                 p3.amoprighttype = p2.amoprighttype AND
                 p3.amopstrategy = 3);
 amoplefttype | amoprighttype | amoprighttype 
--------------+---------------+---------------
(0 rows)

-- We also expect that built-in multiple-datatype hash opfamilies provide
-- complete sets of cross-type operators.  Again, this isn't required, but
-- it is reasonable to expect it for built-in opfamilies.
-- if same family has x=x and y=y, it should have x=y
SELECT p1.amoplefttype, p2.amoplefttype
FROM pg_amop AS p1, pg_amop AS p2
WHERE p1.amopfamily = p2.amopfamily AND
    p1.amoplefttype = p1.amoprighttype AND
    p2.amoplefttype = p2.amoprighttype AND
    p1.amopmethod = (SELECT oid FROM pg_am WHERE amname = 'hash') AND
    p2.amopmethod = (SELECT oid FROM pg_am WHERE amname = 'hash') AND
    p1.amopstrategy = 1 AND p2.amopstrategy = 1 AND
    p1.amoplefttype != p2.amoplefttype AND
    NOT EXISTS(SELECT 1 FROM pg_amop p3 WHERE
                 p3.amopfamily = p1.amopfamily AND
                 p3.amoplefttype = p1.amoplefttype AND
                 p3.amoprighttype = p2.amoplefttype AND
                 p3.amopstrategy = 1);
 amoplefttype | amoplefttype 
--------------+--------------
(0 rows)

-- **************** pg_amproc ****************
-- Look for illegal values in pg_amproc fields
SELECT p1.amprocfamily, p1.amprocnum
FROM pg_amproc as p1
WHERE p1.amprocfamily = 0 OR p1.amproclefttype = 0 OR p1.amprocrighttype = 0
    OR p1.amprocnum < 1 OR p1.amproc = 0;
 amprocfamily | amprocnum 
--------------+-----------
(0 rows)

-- Cross-check amprocnum index against parent AM
SELECT p1.amprocfamily, p1.amprocnum, p2.oid, p2.amname
FROM pg_amproc AS p1, pg_am AS p2, pg_opfamily AS p3
WHERE p1.amprocfamily = p3.oid AND p3.opfmethod = p2.oid AND
    p1.amprocnum > p2.amsupport;
 amprocfamily | amprocnum | oid | amname 
--------------+-----------+-----+--------
(0 rows)

-- Detect missing pg_amproc entries: should have as many support functions
-- as AM expects for each datatype combination supported by the opfamily.
-- btree/GiST/GIN each allow one optional support function, though.
SELECT p1.amname, p2.opfname, p3.amproclefttype, p3.amprocrighttype
FROM pg_am AS p1, pg_opfamily AS p2, pg_amproc AS p3
WHERE p2.opfmethod = p1.oid AND p3.amprocfamily = p2.oid AND
    (SELECT count(*) FROM pg_amproc AS p4
     WHERE p4.amprocfamily = p2.oid AND
           p4.amproclefttype = p3.amproclefttype AND
           p4.amprocrighttype = p3.amprocrighttype)
    NOT BETWEEN
      (CASE WHEN p1.amname IN ('btree', 'gist', 'gin') THEN p1.amsupport - 1
            ELSE p1.amsupport END)
      AND p1.amsupport;
 amname | opfname | amproclefttype | amprocrighttype 
--------+---------+----------------+-----------------
(0 rows)

-- Also, check if there are any pg_opclass entries that don't seem to have
-- pg_amproc support.  Again, opclasses with an optional support proc have
-- to be checked specially.
SELECT amname, opcname, count(*)
FROM pg_am am JOIN pg_opclass op ON opcmethod = am.oid
     LEFT JOIN pg_amproc p ON amprocfamily = opcfamily AND
         amproclefttype = amprocrighttype AND amproclefttype = opcintype
WHERE am.amname <> 'btree' AND am.amname <> 'gist' AND am.amname <> 'gin'
GROUP BY amname, amsupport, opcname, amprocfamily
HAVING count(*) != amsupport OR amprocfamily IS NULL;
 amname | opcname | count 
--------+---------+-------
(0 rows)

SELECT amname, opcname, count(*)
FROM pg_am am JOIN pg_opclass op ON opcmethod = am.oid
     LEFT JOIN pg_amproc p ON amprocfamily = opcfamily AND
         amproclefttype = amprocrighttype AND amproclefttype = opcintype
WHERE am.amname = 'btree' OR am.amname = 'gist' OR am.amname = 'gin'
GROUP BY amname, amsupport, opcname, amprocfamily
HAVING (count(*) != amsupport AND count(*) != amsupport - 1)
    OR amprocfamily IS NULL;
 amname | opcname | count 
--------+---------+-------
(0 rows)

-- Unfortunately, we can't check the amproc link very well because the
-- signature of the function may be different for different support routines
-- or different base data types.
-- We can check that all the referenced instances of the same support
-- routine number take the same number of parameters, but that's about it
-- for a general check...
SELECT p1.amprocfamily, p1.amprocnum,
	p2.oid, p2.proname,
	p3.opfname,
	p4.amprocfamily, p4.amprocnum,
	p5.oid, p5.proname,
	p6.opfname
FROM pg_amproc AS p1, pg_proc AS p2, pg_opfamily AS p3,
     pg_amproc AS p4, pg_proc AS p5, pg_opfamily AS p6
WHERE p1.amprocfamily = p3.oid AND p4.amprocfamily = p6.oid AND
    p3.opfmethod = p6.opfmethod AND p1.amprocnum = p4.amprocnum AND
    p1.amproc = p2.oid AND p4.amproc = p5.oid AND
    (p2.proretset OR p5.proretset OR p2.pronargs != p5.pronargs);
 amprocfamily | amprocnum | oid | proname | opfname | amprocfamily | amprocnum | oid | proname | opfname 
--------------+-----------+-----+---------+---------+--------------+-----------+-----+---------+---------
(0 rows)

-- For btree, though, we can do better since we know the support routines
-- must be of the form cmp(lefttype, righttype) returns int4
-- or sortsupport(internal) returns void.
SELECT p1.amprocfamily, p1.amprocnum,
	p2.oid, p2.proname,
	p3.opfname
FROM pg_amproc AS p1, pg_proc AS p2, pg_opfamily AS p3
WHERE p3.opfmethod = (SELECT oid FROM pg_am WHERE amname = 'btree')
    AND p1.amprocfamily = p3.oid AND p1.amproc = p2.oid AND
    (CASE WHEN amprocnum = 1
          THEN prorettype != 'int4'::regtype OR proretset OR pronargs != 2
               OR proargtypes[0] != amproclefttype
               OR proargtypes[1] != amprocrighttype
          WHEN amprocnum = 2
          THEN prorettype != 'void'::regtype OR proretset OR pronargs != 1
               OR proargtypes[0] != 'internal'::regtype
          ELSE true END);
 amprocfamily | amprocnum | oid | proname | opfname 
--------------+-----------+-----+---------+---------
(0 rows)

-- For hash we can also do a little better: the support routines must be
-- of the form hash(lefttype) returns int4.  There are several cases where
-- we cheat and use a hash function that is physically compatible with the
-- datatype even though there's no cast, so this check does find a small
-- number of entries.
SELECT p1.amprocfamily, p1.amprocnum, p2.proname, p3.opfname
FROM pg_amproc AS p1, pg_proc AS p2, pg_opfamily AS p3
WHERE p3.opfmethod = (SELECT oid FROM pg_am WHERE amname = 'hash')
    AND p1.amprocfamily = p3.oid AND p1.amproc = p2.oid AND
    (amprocnum != 1
     OR proretset
     OR prorettype != 'int4'::regtype
     OR pronargs != 1
     OR NOT physically_coercible(amproclefttype, proargtypes[0])
     OR amproclefttype != amprocrighttype)
ORDER BY 1;
 amprocfamily | amprocnum |    proname     |     opfname     
--------------+-----------+----------------+-----------------
          435 |         1 | hashint4       | date_ops
         1999 |         1 | timestamp_hash | timestamptz_ops
         2222 |         1 | hashchar       | bool_ops
         2223 |         1 | hashvarlena    | bytea_ops
         2225 |         1 | hashint4       | xid_ops
         2226 |         1 | hashint4       | cid_ops
(6 rows)

-- We can also check SP-GiST carefully, since the support routine signatures
-- are independent of the datatype being indexed.
SELECT p1.amprocfamily, p1.amprocnum,
	p2.oid, p2.proname,
	p3.opfname
FROM pg_amproc AS p1, pg_proc AS p2, pg_opfamily AS p3
WHERE p3.opfmethod = (SELECT oid FROM pg_am WHERE amname = 'spgist')
    AND p1.amprocfamily = p3.oid AND p1.amproc = p2.oid AND
    (CASE WHEN amprocnum = 1 OR amprocnum = 2 OR amprocnum = 3 OR amprocnum = 4
          THEN prorettype != 'void'::regtype OR proretset OR pronargs != 2
               OR proargtypes[0] != 'internal'::regtype
               OR proargtypes[1] != 'internal'::regtype
          WHEN amprocnum = 5
          THEN prorettype != 'bool'::regtype OR proretset OR pronargs != 2
               OR proargtypes[0] != 'internal'::regtype
               OR proargtypes[1] != 'internal'::regtype
          ELSE true END);
 amprocfamily | amprocnum | oid | proname | opfname 
--------------+-----------+-----+---------+---------
(0 rows)

-- Support routines that are primary members of opfamilies must be immutable
-- (else it suggests that the index ordering isn't fixed).  But cross-type
-- members need only be stable, since they are just shorthands
-- for index probe queries.
SELECT p1.amprocfamily, p1.amproc, p2.prosrc
FROM pg_amproc AS p1, pg_proc AS p2
WHERE p1.amproc = p2.oid AND
    p1.amproclefttype = p1.amprocrighttype AND
    p2.provolatile != 'i';
 amprocfamily | amproc | prosrc 
--------------+--------+--------
(0 rows)

SELECT p1.amprocfamily, p1.amproc, p2.prosrc
FROM pg_amproc AS p1, pg_proc AS p2
WHERE p1.amproc = p2.oid AND
    p1.amproclefttype != p1.amprocrighttype AND
    p2.provolatile = 'v';
 amprocfamily | amproc | prosrc 
--------------+--------+--------
(0 rows)