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Mark bpchareq not hashjoinable, since it strips trailing blanks

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before comparison; if fields being joined are different widths then hashing
will yield wrong answer.  Also, remove hashjoinable mark from all uses of
array_eq, because array structures may have padding bytes between elements
and the pad bytes are of uncertain content.  This could be revisited if
array code is cleaned up.
Modify opr_sanity regress test to complain if array_eq operator is marked
hashjoinable.
This commit is contained in:
Tom Lane
1999-09-06 21:16:20 +00:00
parent 22fe3d4b04
commit d2f7d1f346
3 changed files with 48 additions and 38 deletions
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13
src/test/regress/expected/opr_sanity.out
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@@ -237,14 +237,11 @@ WHERE p1.oprcanhash AND NOT
1137|=
(2 rows)
QUERY: SELECT p1.oid, p1.oprcanhash, p2.oid, p2.oprcanhash, t1.typname, t2.typname
FROM pg_operator AS p1, pg_operator AS p2, pg_type AS t1, pg_type AS t2
WHERE p1.oprname = '=' AND p1.oprleft = p1.oprright AND
p2.oprname = '=' AND p2.oprleft = p2.oprright AND
p1.oprleft = t1.oid AND p2.oprleft = t2.oid AND t1.typelem = t2.oid AND
p1.oprcanhash != p2.oprcanhash;
oid|oprcanhash|oid|oprcanhash|typname|typname
---+----------+---+----------+-------+-------
QUERY: SELECT p1.oid, p1.oprname
FROM pg_operator AS p1, pg_proc AS p2
WHERE p1.oprcanhash AND p1.oprcode = p2.oid AND p2.proname = 'array_eq';
oid|oprname
---+-------
(0 rows)
QUERY: SELECT p1.oid, p1.oprname, p2.oid, p2.proname

29
src/test/regress/sql/opr_sanity.sql
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@@ -240,15 +240,28 @@ 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);
-- Look for array equality operators that are hashable when the underlying
-- type is not, or vice versa. This is presumably bogus.
-- 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
-- an array is a hashable element type *and* no padding between elements in
-- the array storage (or, perhaps, guaranteed-zero padding). Currently,
-- since the padding code in arrayfuncs.c is pretty bogus, it seems safest
-- to just forbid hashjoin on array equality ops.
-- This should be reconsidered someday.
SELECT p1.oid, p1.oprcanhash, p2.oid, p2.oprcanhash, t1.typname, t2.typname
FROM pg_operator AS p1, pg_operator AS p2, pg_type AS t1, pg_type AS t2
WHERE p1.oprname = '=' AND p1.oprleft = p1.oprright AND
p2.oprname = '=' AND p2.oprleft = p2.oprright AND
p1.oprleft = t1.oid AND p2.oprleft = t2.oid AND t1.typelem = t2.oid AND
p1.oprcanhash != p2.oprcanhash;
-- -- Look for array equality operators that are hashable when the underlying
-- -- type is not, or vice versa. This is presumably bogus.
--
-- SELECT p1.oid, p1.oprcanhash, p2.oid, p2.oprcanhash, t1.typname, t2.typname
-- FROM pg_operator AS p1, pg_operator AS p2, pg_type AS t1, pg_type AS t2
-- WHERE p1.oprname = '=' AND p1.oprleft = p1.oprright AND
-- p2.oprname = '=' AND p2.oprleft = p2.oprright AND
-- p1.oprleft = t1.oid AND p2.oprleft = t2.oid AND t1.typelem = t2.oid AND
-- p1.oprcanhash != p2.oprcanhash;
-- Substitute check: forbid hashable array ops, period.
SELECT p1.oid, p1.oprname
FROM pg_operator AS p1, pg_proc AS p2
WHERE p1.oprcanhash AND p1.oprcode = p2.oid AND p2.proname = 'array_eq';
-- Check that each operator defined in pg_operator matches its oprcode entry
-- in pg_proc. Easiest to do this separately for each oprkind.