Adjust collation determination rules as per discussion.

Remove crude hack that tried to propagate collation through a
function-returning-record, ie, from the function's arguments to individual
fields selected from its result record.  That is just plain inconsistent,
because the function result is composite and cannot have a collation;
and there's no hope of making this kind of action-at-a-distance work
consistently.  Adjust regression test cases that expected this to happen.

Meanwhile, the behavior of casting to a domain with a declared collation
stays the same as it was, since that seemed to be the consensus.

diff --git a/src/backend/parser/parse_collate.c b/src/backend/parser/parse_collate.c
index 8860679ccb9e163e8d3fa4929252aec81bdc5e07..3e557db266806dce6e76d6189ecc1ef4a3dda852 100644 (file)
--- a/src/backend/parser/parse_collate.c
+++ b/src/backend/parser/parse_collate.c
@@ -289,10 +289,11 @@ assign_collations_walker(Node *node, assign_collations_context *context)
                case T_FieldSelect:
                        {
                                /*
-                                * FieldSelect is a special case because the field may have
-                                * a non-default collation, in which case we should use that.
-                                * The field's collation was already looked up and saved
-                                * in the node.
+                                * For FieldSelect, the result has the field's declared
+                                * collation, independently of what happened in the arguments.
+                                * (The immediate argument must be composite and thus not
+                                * collatable, anyhow.)  The field's collation was already
+                                * looked up and saved in the node.
                                 */
                                FieldSelect *expr = (FieldSelect *) node;
 
@@ -304,24 +305,6 @@ assign_collations_walker(Node *node, assign_collations_context *context)
                                if (OidIsValid(expr->resultcollid))
                                {
                                        /* Node's result type is collatable. */
-                                       if (expr->resultcollid == DEFAULT_COLLATION_OID)
-                                       {
-                                               /*
-                                                * The immediate input node necessarily yields a
-                                                * composite type, so it will have no exposed
-                                                * collation.  However, if we are selecting a field
-                                                * from a function returning composite, see if we
-                                                * can bubble up a collation from the function's
-                                                * input.  XXX this is a bit of a hack, rethink ...
-                                                */
-                                               if (IsA(expr->arg, FuncExpr))
-                                               {
-                                                       FuncExpr *fexpr = (FuncExpr *) expr->arg;
-
-                                                       if (OidIsValid(fexpr->inputcollid))
-                                                               expr->resultcollid = fexpr->inputcollid;
-                                               }
-                                       }
                                        /* Pass up field's collation as an implicit choice. */
                                        collation = expr->resultcollid;
                                        strength = COLLATE_IMPLICIT;

diff --git a/src/backend/parser/parse_func.c b/src/backend/parser/parse_func.c
index a187287e2830c2db907cf531c2bcdb4cfaee47d8..ba699e9a1ed929dd97a79d42ce69a4dca0003d78 100644 (file)
--- a/src/backend/parser/parse_func.c
+++ b/src/backend/parser/parse_func.c
@@ -1384,7 +1384,7 @@ ParseComplexProjection(ParseState *pstate, char *funcname, Node *first_arg,
                        fselect->fieldnum = i + 1;
                        fselect->resulttype = att->atttypid;
                        fselect->resulttypmod = att->atttypmod;
-                       /* resultcollid may get overridden by parse_collate.c */
+                       /* save attribute's collation for parse_collate.c */
                        fselect->resultcollid = att->attcollation;
                        return (Node *) fselect;
                }

diff --git a/src/backend/parser/parse_target.c b/src/backend/parser/parse_target.c
index d53d1d9f00822b8115d0c3f8edacf580cec9be91..52c6db2eb5cae4780abca4bb34f1f6d063af6ecb 100644 (file)
--- a/src/backend/parser/parse_target.c
+++ b/src/backend/parser/parse_target.c
@@ -1290,7 +1290,7 @@ ExpandRowReference(ParseState *pstate, Node *expr,
                fselect->fieldnum = i + 1;
                fselect->resulttype = att->atttypid;
                fselect->resulttypmod = att->atttypmod;
-               /* resultcollid may get overridden by parse_collate.c */
+               /* save attribute's collation for parse_collate.c */
                fselect->resultcollid = att->attcollation;
 
                if (targetlist)

diff --git a/src/test/regress/expected/collate.linux.utf8.out b/src/test/regress/expected/collate.linux.utf8.out
index a4ec1e9080146eac82dad30d7084d0817c858886..fe4d27e34b1b507f0a2e63cef41a5e438e082e64 100644 (file)
--- a/src/test/regress/expected/collate.linux.utf8.out
+++ b/src/test/regress/expected/collate.linux.utf8.out
@@ -771,33 +771,33 @@ SELECT * FROM unnest((SELECT array_agg(b ORDER BY b) FROM collate_test3)) ORDER
  äbc
 (4 rows)
 
-CREATE FUNCTION dup (f1 anyelement, f2 out anyelement, f3 out anyarray)
-    AS 'select $1, array[$1,$1]' LANGUAGE sql;
-SELECT a, (dup(b)).* FROM collate_test1 ORDER BY 2;
- a | f2  |    f3     
----+-----+-----------
- 1 | abc | {abc,abc}
- 4 | ABC | {ABC,ABC}
- 2 | äbc | {äbc,äbc}
- 3 | bbc | {bbc,bbc}
-(4 rows)
-
-SELECT a, (dup(b)).* FROM collate_test2 ORDER BY 2;
- a | f2  |    f3     
----+-----+-----------
- 1 | abc | {abc,abc}
- 4 | ABC | {ABC,ABC}
- 3 | bbc | {bbc,bbc}
- 2 | äbc | {äbc,äbc}
-(4 rows)
-
-SELECT a, (dup(b)).* FROM collate_test3 ORDER BY 2;
- a | f2  |    f3     
----+-----+-----------
- 4 | ABC | {ABC,ABC}
- 1 | abc | {abc,abc}
- 3 | bbc | {bbc,bbc}
- 2 | äbc | {äbc,äbc}
+CREATE FUNCTION dup (anyelement) RETURNS anyelement
+    AS 'select $1' LANGUAGE sql;
+SELECT a, dup(b) FROM collate_test1 ORDER BY 2;
+ a | dup 
+---+-----
+ 1 | abc
+ 4 | ABC
+ 2 | äbc
+ 3 | bbc
+(4 rows)
+
+SELECT a, dup(b) FROM collate_test2 ORDER BY 2;
+ a | dup 
+---+-----
+ 1 | abc
+ 4 | ABC
+ 3 | bbc
+ 2 | äbc
+(4 rows)
+
+SELECT a, dup(b) FROM collate_test3 ORDER BY 2;
+ a | dup 
+---+-----
+ 4 | ABC
+ 1 | abc
+ 3 | bbc
+ 2 | äbc
 (4 rows)
 
 -- indexes

diff --git a/src/test/regress/expected/collate.out b/src/test/regress/expected/collate.out
index f1a025ae3731485dff7644c43fadaf2f3ccf74e1..230eb9ef3157affd764e55f745f2b68ad18f27cc 100644 (file)
--- a/src/test/regress/expected/collate.out
+++ b/src/test/regress/expected/collate.out
@@ -502,24 +502,24 @@ SELECT * FROM unnest((SELECT array_agg(b ORDER BY b) FROM collate_test2)) ORDER
  bbc
 (4 rows)
 
-CREATE FUNCTION dup (f1 anyelement, f2 out anyelement, f3 out anyarray)
-    AS 'select $1, array[$1,$1]' LANGUAGE sql;
-SELECT a, (dup(b)).* FROM collate_test1 ORDER BY 2;
- a | f2  |    f3     
----+-----+-----------
- 4 | ABD | {ABD,ABD}
- 2 | Abc | {Abc,Abc}
- 1 | abc | {abc,abc}
- 3 | bbc | {bbc,bbc}
+CREATE FUNCTION dup (anyelement) RETURNS anyelement
+    AS 'select $1' LANGUAGE sql;
+SELECT a, dup(b) FROM collate_test1 ORDER BY 2;
+ a | dup 
+---+-----
+ 4 | ABD
+ 2 | Abc
+ 1 | abc
+ 3 | bbc
 (4 rows)
 
-SELECT a, (dup(b)).* FROM collate_test2 ORDER BY 2;
- a | f2  |    f3     
----+-----+-----------
- 4 | ABD | {ABD,ABD}
- 2 | Abc | {Abc,Abc}
- 1 | abc | {abc,abc}
- 3 | bbc | {bbc,bbc}
+SELECT a, dup(b) FROM collate_test2 ORDER BY 2;
+ a | dup 
+---+-----
+ 4 | ABD
+ 2 | Abc
+ 1 | abc
+ 3 | bbc
 (4 rows)
 
 -- indexes

diff --git a/src/test/regress/sql/collate.linux.utf8.sql b/src/test/regress/sql/collate.linux.utf8.sql
index 265db722202a40481b6f04633046eb9ce7ec37ef..57f5947aa9db83de74200e99cf020a4ed7eee786 100644 (file)
--- a/src/test/regress/sql/collate.linux.utf8.sql
+++ b/src/test/regress/sql/collate.linux.utf8.sql
@@ -242,12 +242,12 @@ SELECT * FROM unnest((SELECT array_agg(b ORDER BY b) FROM collate_test1)) ORDER
 SELECT * FROM unnest((SELECT array_agg(b ORDER BY b) FROM collate_test2)) ORDER BY 1;
 SELECT * FROM unnest((SELECT array_agg(b ORDER BY b) FROM collate_test3)) ORDER BY 1;
 
-CREATE FUNCTION dup (f1 anyelement, f2 out anyelement, f3 out anyarray)
-    AS 'select $1, array[$1,$1]' LANGUAGE sql;
+CREATE FUNCTION dup (anyelement) RETURNS anyelement
+    AS 'select $1' LANGUAGE sql;
 
-SELECT a, (dup(b)).* FROM collate_test1 ORDER BY 2;
-SELECT a, (dup(b)).* FROM collate_test2 ORDER BY 2;
-SELECT a, (dup(b)).* FROM collate_test3 ORDER BY 2;
+SELECT a, dup(b) FROM collate_test1 ORDER BY 2;
+SELECT a, dup(b) FROM collate_test2 ORDER BY 2;
+SELECT a, dup(b) FROM collate_test3 ORDER BY 2;
 
 
 -- indexes

diff --git a/src/test/regress/sql/collate.sql b/src/test/regress/sql/collate.sql
index c904aa77f37f19b49b0507387d00b6f79cf1c218..39c22674b9caf5990aefc4263664c94624201595 100644 (file)
--- a/src/test/regress/sql/collate.sql
+++ b/src/test/regress/sql/collate.sql
@@ -168,11 +168,11 @@ SELECT a, CAST(b AS varchar) FROM collate_test2 ORDER BY 2;
 SELECT * FROM unnest((SELECT array_agg(b ORDER BY b) FROM collate_test1)) ORDER BY 1;
 SELECT * FROM unnest((SELECT array_agg(b ORDER BY b) FROM collate_test2)) ORDER BY 1;
 
-CREATE FUNCTION dup (f1 anyelement, f2 out anyelement, f3 out anyarray)
-    AS 'select $1, array[$1,$1]' LANGUAGE sql;
+CREATE FUNCTION dup (anyelement) RETURNS anyelement
+    AS 'select $1' LANGUAGE sql;
 
-SELECT a, (dup(b)).* FROM collate_test1 ORDER BY 2;
-SELECT a, (dup(b)).* FROM collate_test2 ORDER BY 2;
+SELECT a, dup(b) FROM collate_test1 ORDER BY 2;
+SELECT a, dup(b) FROM collate_test2 ORDER BY 2;
 
 
 -- indexes