Mark bpchareq not hashjoinable, since it strips trailing blanks

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.

src/include/catalog/pg_operator.h

@@ -7,7 +7,7 @@
  *
  * Copyright (c) 1994, Regents of the University of California
  *
- * $Id: pg_operator.h,v 1.58 1999/07/27 03:51:11 tgl Exp $
+ * $Id: pg_operator.h,v 1.59 1999/09/06 21:16:18 tgl Exp $
  *
  * NOTES
  *	  the genbki.sh script reads this file and generates .bki
@@ -109,32 +109,32 @@ DATA(insert OID =  96 ( "="		   PGUID 0 b t t  23  23  16  96 518  97  97 int4eq
 DATA(insert OID =  97 ( "<"		   PGUID 0 b t f  23  23  16 521 525   0   0 int4lt intltsel intltjoinsel ));
 DATA(insert OID =  98 ( "="		   PGUID 0 b t t  25  25  16  98 531 664 664 texteq eqsel eqjoinsel ));
 
-DATA(insert OID = 329 (  "="	   PGUID 0 b t t  1000	1000  16  329 0  0	0 array_eq eqsel eqjoinsel ));
-DATA(insert OID = 349 (  "="	   PGUID 0 b t t  1001	1001  16  349 0  0	0 array_eq eqsel eqjoinsel ));
-DATA(insert OID = 374 (  "="	   PGUID 0 b t t  1002	1002  16  374 0  0	0 array_eq eqsel eqjoinsel ));
-DATA(insert OID = 375 (  "="	   PGUID 0 b t t  1003	1003  16  375 0  0	0 array_eq eqsel eqjoinsel ));
-DATA(insert OID = 377 (  "="	   PGUID 0 b t t  1005	1005  16  377 0  0	0 array_eq eqsel eqjoinsel ));
-DATA(insert OID = 378 (  "="	   PGUID 0 b t t  1006	1006  16  378 0  0	0 array_eq eqsel eqjoinsel ));
-DATA(insert OID = 379 (  "="	   PGUID 0 b t t  1007	1007  16  379 0  0	0 array_eq eqsel eqjoinsel ));
-DATA(insert OID = 380 (  "="	   PGUID 0 b t t  1008	1008  16  380 0  0	0 array_eq eqsel eqjoinsel ));
-DATA(insert OID = 381 (  "="	   PGUID 0 b t t  1009	1009  16  381 0  0	0 array_eq eqsel eqjoinsel ));
-DATA(insert OID = 382 (  "="	   PGUID 0 b t t  1028	1028  16  382 0  0	0 array_eq eqsel eqjoinsel ));
-DATA(insert OID = 383 (  "="	   PGUID 0 b t t  1010	1010  16  383 0  0	0 array_eq eqsel eqjoinsel ));
-DATA(insert OID = 384 (  "="	   PGUID 0 b t t  1011	1011  16  384 0  0	0 array_eq eqsel eqjoinsel ));
-DATA(insert OID = 385 (  "="	   PGUID 0 b t t  1012	1012  16  385 0  0	0 array_eq eqsel eqjoinsel ));
-DATA(insert OID = 386 (  "="	   PGUID 0 b t t  1013	1013  16  386 0  0	0 array_eq eqsel eqjoinsel ));
-DATA(insert OID = 390 (  "="	   PGUID 0 b t t  1017	1017  16  390 0  0	0 array_eq eqsel eqjoinsel ));
+DATA(insert OID = 329 (  "="	   PGUID 0 b t f  1000	1000  16  329 0  0	0 array_eq eqsel eqjoinsel ));
+DATA(insert OID = 349 (  "="	   PGUID 0 b t f  1001	1001  16  349 0  0	0 array_eq eqsel eqjoinsel ));
+DATA(insert OID = 374 (  "="	   PGUID 0 b t f  1002	1002  16  374 0  0	0 array_eq eqsel eqjoinsel ));
+DATA(insert OID = 375 (  "="	   PGUID 0 b t f  1003	1003  16  375 0  0	0 array_eq eqsel eqjoinsel ));
+DATA(insert OID = 377 (  "="	   PGUID 0 b t f  1005	1005  16  377 0  0	0 array_eq eqsel eqjoinsel ));
+DATA(insert OID = 378 (  "="	   PGUID 0 b t f  1006	1006  16  378 0  0	0 array_eq eqsel eqjoinsel ));
+DATA(insert OID = 379 (  "="	   PGUID 0 b t f  1007	1007  16  379 0  0	0 array_eq eqsel eqjoinsel ));
+DATA(insert OID = 380 (  "="	   PGUID 0 b t f  1008	1008  16  380 0  0	0 array_eq eqsel eqjoinsel ));
+DATA(insert OID = 381 (  "="	   PGUID 0 b t f  1009	1009  16  381 0  0	0 array_eq eqsel eqjoinsel ));
+DATA(insert OID = 382 (  "="	   PGUID 0 b t f  1028	1028  16  382 0  0	0 array_eq eqsel eqjoinsel ));
+DATA(insert OID = 383 (  "="	   PGUID 0 b t f  1010	1010  16  383 0  0	0 array_eq eqsel eqjoinsel ));
+DATA(insert OID = 384 (  "="	   PGUID 0 b t f  1011	1011  16  384 0  0	0 array_eq eqsel eqjoinsel ));
+DATA(insert OID = 385 (  "="	   PGUID 0 b t f  1012	1012  16  385 0  0	0 array_eq eqsel eqjoinsel ));
+DATA(insert OID = 386 (  "="	   PGUID 0 b t f  1013	1013  16  386 0  0	0 array_eq eqsel eqjoinsel ));
+DATA(insert OID = 390 (  "="	   PGUID 0 b t f  1017	1017  16  390 0  0	0 array_eq eqsel eqjoinsel ));
 DATA(insert OID = 391 (  "="	   PGUID 0 b t f  1018	1018  16  391 0  0	0 array_eq eqsel eqjoinsel ));
 DATA(insert OID = 392 (  "="	   PGUID 0 b t f  1019	1019  16  392 0  0	0 array_eq eqsel eqjoinsel ));
 DATA(insert OID = 393 (  "="	   PGUID 0 b t f  1020	1020  16  393 0  0	0 array_eq eqsel eqjoinsel ));
 DATA(insert OID = 394 (  "="	   PGUID 0 b t f  1021	1021  16  394 0  0	0 array_eq eqsel eqjoinsel ));
 DATA(insert OID = 395 (  "="	   PGUID 0 b t f  1022	1022  16  395 0  0	0 array_eq eqsel eqjoinsel ));
-DATA(insert OID = 396 (  "="	   PGUID 0 b t t  1023	1023  16  396 0  0	0 array_eq eqsel eqjoinsel ));
-DATA(insert OID = 397 (  "="	   PGUID 0 b t t  1024	1024  16  397 0  0	0 array_eq eqsel eqjoinsel ));
+DATA(insert OID = 396 (  "="	   PGUID 0 b t f  1023	1023  16  396 0  0	0 array_eq eqsel eqjoinsel ));
+DATA(insert OID = 397 (  "="	   PGUID 0 b t f  1024	1024  16  397 0  0	0 array_eq eqsel eqjoinsel ));
 DATA(insert OID = 398 (  "="	   PGUID 0 b t f  1025	1025  16  398 0  0	0 array_eq eqsel eqjoinsel ));
-DATA(insert OID = 399 (  "="	   PGUID 0 b t t  1026	1026  16  399 0  0	0 array_eq eqsel eqjoinsel ));
-DATA(insert OID = 400 (  "="	   PGUID 0 b t t  1027	1027  16  400 0  0	0 array_eq eqsel eqjoinsel ));
-DATA(insert OID = 401 (  "="	   PGUID 0 b t t  1034	1034  16  401 0  0	0 array_eq eqsel eqjoinsel ));
+DATA(insert OID = 399 (  "="	   PGUID 0 b t f  1026	1026  16  399 0  0	0 array_eq eqsel eqjoinsel ));
+DATA(insert OID = 400 (  "="	   PGUID 0 b t f  1027	1027  16  400 0  0	0 array_eq eqsel eqjoinsel ));
+DATA(insert OID = 401 (  "="	   PGUID 0 b t f  1034	1034  16  401 0  0	0 array_eq eqsel eqjoinsel ));
 
 DATA(insert OID = 410 ( "="		   PGUID 0 b t t  20  20  16 410 411 412 412 int8eq eqsel eqjoinsel ));
 DATA(insert OID = 411 ( "<>"	   PGUID 0 b t f  20  20  16 411 410 0 0 int8ne neqsel neqjoinsel ));
@@ -434,7 +434,7 @@ DATA(insert OID =  971 (  "@@"	   PGUID 0 l t f	0  604	600    0  0 0 0 poly_cent
 DATA(insert OID =  974 (  "||"	   PGUID 0 b t f 1042 1042 1042    0  0 0 0 textcat - - ));
 DATA(insert OID =  979 (  "||"	   PGUID 0 b t f 1043 1043 1043    0  0 0 0 textcat - - ));
 
-DATA(insert OID = 1054 ( "="	   PGUID 0 b t t 1042 1042	 16 1054 1057 1058 1058 bpchareq eqsel eqjoinsel ));
+DATA(insert OID = 1054 ( "="	   PGUID 0 b t f 1042 1042	 16 1054 1057 1058 1058 bpchareq eqsel eqjoinsel ));
 DATA(insert OID = 1055 ( "~"	   PGUID 0 b t f 1042	25	 16    0 1056  0 0 textregexeq eqsel eqjoinsel ));
 #define OID_BPCHAR_REGEXEQ_OP		1055
 DATA(insert OID = 1056 ( "!~"	   PGUID 0 b t f 1042	25	 16    0 1055  0 0 textregexne neqsel neqjoinsel ));

src/test/regress/expected/opr_sanity.out

@@ -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

src/test/regress/sql/opr_sanity.sql

@@ -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.
-
-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;
+-- 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.
+
+-- -- 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.