From b0c451e145be23211dce0718cc63e632959591e8 Mon Sep 17 00:00:00 2001
From: Tom Lane <tgl@sss.pgh.pa.us>
Date: Thu, 5 Aug 2010 18:21:19 +0000
Subject: [PATCH] Remove the single-argument form of string_agg(). It added
nothing much in functionality, while creating an ambiguity in usage with
ORDER BY that at least two people have already gotten seriously confused by.
Also, add an opr_sanity test to check that we don't in future violate the
newly minted policy of not having built-in aggregates with the same name and
different numbers of parameters. Per discussion of a complaint from Thom
Brown.
---
doc/src/sgml/func.sgml | 12 +++++-----
doc/src/sgml/syntax.sgml | 11 +++++----
src/backend/utils/adt/varlena.c | 26 ++------------------
src/include/catalog/catversion.h | 4 ++--
src/include/catalog/pg_aggregate.h | 5 ++--
src/include/catalog/pg_proc.h | 12 ++++------
src/include/utils/builtins.h | 6 +----
src/test/regress/expected/aggregates.out | 30 ++++++++++--------------
src/test/regress/expected/opr_sanity.out | 25 ++++++++++++++++++++
src/test/regress/sql/aggregates.sql | 11 ++++-----
src/test/regress/sql/opr_sanity.sql | 20 ++++++++++++++++
11 files changed, 85 insertions(+), 77 deletions(-)
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 07ff132cbb5..b981ca7f920 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -1,4 +1,4 @@
-<!-- $PostgreSQL: pgsql/doc/src/sgml/func.sgml,v 1.523 2010/08/05 04:21:53 petere Exp $ -->
+<!-- $PostgreSQL: pgsql/doc/src/sgml/func.sgml,v 1.524 2010/08/05 18:21:17 tgl Exp $ -->
<chapter id="functions">
<title>Functions and Operators</title>
@@ -9782,7 +9782,7 @@ SELECT NULLIF(value, '(none)') ...
<thead>
<row>
<entry>Function</entry>
- <entry>Argument Type</entry>
+ <entry>Argument Type(s)</entry>
<entry>Return Type</entry>
<entry>Description</entry>
</row>
@@ -9952,17 +9952,17 @@ SELECT NULLIF(value, '(none)') ...
<primary>string_agg</primary>
</indexterm>
<function>
- string_agg(<replaceable class="parameter">expression</replaceable>
- [, <replaceable class="parameter">delimiter</replaceable> ] )
+ string_agg(<replaceable class="parameter">expression</replaceable>,
+ <replaceable class="parameter">delimiter</replaceable>)
</function>
</entry>
<entry>
- <type>text</type>
+ <type>text</type>, <type>text</type>
</entry>
<entry>
<type>text</type>
</entry>
- <entry>input values concatenated into a string, optionally with delimiters</entry>
+ <entry>input values concatenated into a string, separated by delimiter</entry>
</row>
<row>
diff --git a/doc/src/sgml/syntax.sgml b/doc/src/sgml/syntax.sgml
index 16aa89f497f..ee2c5214aa9 100644
--- a/doc/src/sgml/syntax.sgml
+++ b/doc/src/sgml/syntax.sgml
@@ -1,4 +1,4 @@
-<!-- $PostgreSQL: pgsql/doc/src/sgml/syntax.sgml,v 1.149 2010/08/04 15:27:57 tgl Exp $ -->
+<!-- $PostgreSQL: pgsql/doc/src/sgml/syntax.sgml,v 1.150 2010/08/05 18:21:17 tgl Exp $ -->
<chapter id="sql-syntax">
<title>SQL Syntax</title>
@@ -1583,16 +1583,17 @@ SELECT array_agg(a ORDER BY b DESC) FROM table;
<para>
When dealing with multiple-argument aggregate functions, note that the
<literal>ORDER BY</> clause goes after all the aggregate arguments.
- For example, this:
+ For example, write this:
<programlisting>
SELECT string_agg(a, ',' ORDER BY a) FROM table;
</programlisting>
not this:
<programlisting>
-SELECT string_agg(a ORDER BY a, ',') FROM table; -- not what you want
+SELECT string_agg(a ORDER BY a, ',') FROM table; -- incorrect
</programlisting>
- The latter syntax will be accepted, but <literal>','</> will be
- treated as a (useless) sort key.
+ The latter is syntactically valid, but it represents a call of a
+ single-argument aggregate function with two <literal>ORDER BY</> keys
+ (the second one being rather useless since it's a constant).
</para>
<para>
diff --git a/src/backend/utils/adt/varlena.c b/src/backend/utils/adt/varlena.c
index be41c977ffb..e9f9f597ec7 100644
--- a/src/backend/utils/adt/varlena.c
+++ b/src/backend/utils/adt/varlena.c
@@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/backend/utils/adt/varlena.c,v 1.177 2010/02/26 02:01:10 momjian Exp $
+ * $PostgreSQL: pgsql/src/backend/utils/adt/varlena.c,v 1.178 2010/08/05 18:21:17 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -3320,7 +3320,7 @@ pg_column_size(PG_FUNCTION_ARGS)
/*
* string_agg - Concatenates values and returns string.
*
- * Syntax: string_agg(value text, delimiter text = '') RETURNS text
+ * Syntax: string_agg(value text, delimiter text) RETURNS text
*
* Note: Any NULL values are ignored. The first-call delimiter isn't
* actually used at all, and on subsequent calls the delimiter precedes
@@ -3359,28 +3359,6 @@ string_agg_transfn(PG_FUNCTION_ARGS)
state = PG_ARGISNULL(0) ? NULL : (StringInfo) PG_GETARG_POINTER(0);
- /* Append the element unless null. */
- if (!PG_ARGISNULL(1))
- {
- if (state == NULL)
- state = makeStringAggState(fcinfo);
- appendStringInfoText(state, PG_GETARG_TEXT_PP(1)); /* value */
- }
-
- /*
- * The transition type for string_agg() is declared to be "internal",
- * which is a pass-by-value type the same size as a pointer.
- */
- PG_RETURN_POINTER(state);
-}
-
-Datum
-string_agg_delim_transfn(PG_FUNCTION_ARGS)
-{
- StringInfo state;
-
- state = PG_ARGISNULL(0) ? NULL : (StringInfo) PG_GETARG_POINTER(0);
-
/* Append the value unless null. */
if (!PG_ARGISNULL(1))
{
diff --git a/src/include/catalog/catversion.h b/src/include/catalog/catversion.h
index a1a223b227d..69e87bb5850 100644
--- a/src/include/catalog/catversion.h
+++ b/src/include/catalog/catversion.h
@@ -37,7 +37,7 @@
* Portions Copyright (c) 1996-2010, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
- * $PostgreSQL: pgsql/src/include/catalog/catversion.h,v 1.589 2010/08/05 04:21:54 petere Exp $
+ * $PostgreSQL: pgsql/src/include/catalog/catversion.h,v 1.590 2010/08/05 18:21:17 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -53,6 +53,6 @@
*/
/* yyyymmddN */
-#define CATALOG_VERSION_NO 201008051
+#define CATALOG_VERSION_NO 201008052
#endif
diff --git a/src/include/catalog/pg_aggregate.h b/src/include/catalog/pg_aggregate.h
index c47adbe4755..0fc28df804d 100644
--- a/src/include/catalog/pg_aggregate.h
+++ b/src/include/catalog/pg_aggregate.h
@@ -8,7 +8,7 @@
* Portions Copyright (c) 1996-2010, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
- * $PostgreSQL: pgsql/src/include/catalog/pg_aggregate.h,v 1.71 2010/02/01 03:14:43 itagaki Exp $
+ * $PostgreSQL: pgsql/src/include/catalog/pg_aggregate.h,v 1.72 2010/08/05 18:21:17 tgl Exp $
*
* NOTES
* the genbki.pl script reads this file and generates .bki
@@ -224,8 +224,7 @@ DATA(insert ( 2901 xmlconcat2 - 0 142 _null_ ));
DATA(insert ( 2335 array_agg_transfn array_agg_finalfn 0 2281 _null_ ));
/* text */
-DATA(insert (3537 string_agg_transfn string_agg_finalfn 0 2281 _null_ ));
-DATA(insert (3538 string_agg_delim_transfn string_agg_finalfn 0 2281 _null_ ));
+DATA(insert ( 3538 string_agg_transfn string_agg_finalfn 0 2281 _null_ ));
/*
* prototypes for functions in pg_aggregate.c
diff --git a/src/include/catalog/pg_proc.h b/src/include/catalog/pg_proc.h
index 8b9e1db5815..ffea7c9b57c 100644
--- a/src/include/catalog/pg_proc.h
+++ b/src/include/catalog/pg_proc.h
@@ -7,7 +7,7 @@
* Portions Copyright (c) 1996-2010, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
- * $PostgreSQL: pgsql/src/include/catalog/pg_proc.h,v 1.574 2010/08/05 04:21:54 petere Exp $
+ * $PostgreSQL: pgsql/src/include/catalog/pg_proc.h,v 1.575 2010/08/05 18:21:17 tgl Exp $
*
* NOTES
* The script catalog/genbki.pl reads this file and generates .bki
@@ -2835,16 +2835,12 @@ DATA(insert OID = 2816 ( float8_covar_samp PGNSP PGUID 12 1 0 0 f f f t f i 1
DESCR("COVAR_SAMP(double, double) aggregate final function");
DATA(insert OID = 2817 ( float8_corr PGNSP PGUID 12 1 0 0 f f f t f i 1 0 701 "1022" _null_ _null_ _null_ _null_ float8_corr _null_ _null_ _null_ ));
DESCR("CORR(double, double) aggregate final function");
-DATA(insert OID = 3534 ( string_agg_transfn PGNSP PGUID 12 1 0 0 f f f f f i 2 0 2281 "2281 25" _null_ _null_ _null_ _null_ string_agg_transfn _null_ _null_ _null_ ));
-DESCR("string_agg(text) transition function");
-DATA(insert OID = 3535 ( string_agg_delim_transfn PGNSP PGUID 12 1 0 0 f f f f f i 3 0 2281 "2281 25 25" _null_ _null_ _null_ _null_ string_agg_delim_transfn _null_ _null_ _null_ ));
+DATA(insert OID = 3535 ( string_agg_transfn PGNSP PGUID 12 1 0 0 f f f f f i 3 0 2281 "2281 25 25" _null_ _null_ _null_ _null_ string_agg_transfn _null_ _null_ _null_ ));
DESCR("string_agg(text, text) transition function");
DATA(insert OID = 3536 ( string_agg_finalfn PGNSP PGUID 12 1 0 0 f f f f f i 1 0 25 "2281" _null_ _null_ _null_ _null_ string_agg_finalfn _null_ _null_ _null_ ));
-DESCR("string_agg final function");
-DATA(insert OID = 3537 ( string_agg PGNSP PGUID 12 1 0 0 t f f f f i 1 0 25 "25" _null_ _null_ _null_ _null_ aggregate_dummy _null_ _null_ _null_ ));
-DESCR("concatenate aggregate input into an string");
+DESCR("string_agg(text, text) final function");
DATA(insert OID = 3538 ( string_agg PGNSP PGUID 12 1 0 0 t f f f f i 2 0 25 "25 25" _null_ _null_ _null_ _null_ aggregate_dummy _null_ _null_ _null_ ));
-DESCR("concatenate aggregate input into an string with delimiter");
+DESCR("concatenate aggregate input into a string");
/* To ASCII conversion */
DATA(insert OID = 1845 ( to_ascii PGNSP PGUID 12 1 0 0 f f f t f i 1 0 25 "25" _null_ _null_ _null_ _null_ to_ascii_default _null_ _null_ _null_ ));
diff --git a/src/include/utils/builtins.h b/src/include/utils/builtins.h
index 92b3c64aaad..4ba866453c5 100644
--- a/src/include/utils/builtins.h
+++ b/src/include/utils/builtins.h
@@ -7,7 +7,7 @@
* Portions Copyright (c) 1996-2010, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
- * $PostgreSQL: pgsql/src/include/utils/builtins.h,v 1.352 2010/07/22 01:22:35 rhaas Exp $
+ * $PostgreSQL: pgsql/src/include/utils/builtins.h,v 1.353 2010/08/05 18:21:19 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -729,7 +729,6 @@ extern Datum unknownsend(PG_FUNCTION_ARGS);
extern Datum pg_column_size(PG_FUNCTION_ARGS);
extern Datum string_agg_transfn(PG_FUNCTION_ARGS);
-extern Datum string_agg_delim_transfn(PG_FUNCTION_ARGS);
extern Datum string_agg_finalfn(PG_FUNCTION_ARGS);
/* version.c */
@@ -780,9 +779,6 @@ extern Datum translate(PG_FUNCTION_ARGS);
extern Datum chr (PG_FUNCTION_ARGS);
extern Datum repeat(PG_FUNCTION_ARGS);
extern Datum ascii(PG_FUNCTION_ARGS);
-extern Datum string_agg_transfn(PG_FUNCTION_ARGS);
-extern Datum string_agg_delim_transfn(PG_FUNCTION_ARGS);
-extern Datum string_agg_finalfn(PG_FUNCTION_ARGS);
/* inet_net_ntop.c */
extern char *inet_net_ntop(int af, const void *src, int bits,
diff --git a/src/test/regress/expected/aggregates.out b/src/test/regress/expected/aggregates.out
index 087b4679d4d..b456d7e989a 100644
--- a/src/test/regress/expected/aggregates.out
+++ b/src/test/regress/expected/aggregates.out
@@ -800,12 +800,6 @@ ERROR: in an aggregate with DISTINCT, ORDER BY expressions must appear in argum
LINE 1: select aggfns(distinct a,a,c order by a,b)
^
-- string_agg tests
-select string_agg(a) from (values('aaaa'),('bbbb'),('cccc')) g(a);
- string_agg
---------------
- aaaabbbbcccc
-(1 row)
-
select string_agg(a,',') from (values('aaaa'),('bbbb'),('cccc')) g(a);
string_agg
----------------
@@ -818,10 +812,10 @@ select string_agg(a,',') from (values('aaaa'),(null),('bbbb'),('cccc')) g(a);
aaaa,bbbb,cccc
(1 row)
-select string_agg(a,',') from (values(null),(null),('bbbb'),('cccc')) g(a);
+select string_agg(a,'AB') from (values(null),(null),('bbbb'),('cccc')) g(a);
string_agg
------------
- bbbb,cccc
+ bbbbABcccc
(1 row)
select string_agg(a,',') from (values(null),(null)) g(a);
@@ -831,23 +825,23 @@ select string_agg(a,',') from (values(null),(null)) g(a);
(1 row)
-- check some implicit casting cases, as per bug #5564
-select string_agg(distinct f1 order by f1) from varchar_tbl; -- ok
+select string_agg(distinct f1, ',' order by f1) from varchar_tbl; -- ok
string_agg
------------
- aababcd
+ a,ab,abcd
(1 row)
-select string_agg(distinct f1::text order by f1) from varchar_tbl; -- not ok
+select string_agg(distinct f1::text, ',' order by f1) from varchar_tbl; -- not ok
ERROR: in an aggregate with DISTINCT, ORDER BY expressions must appear in argument list
-LINE 1: select string_agg(distinct f1::text order by f1) from varcha...
- ^
-select string_agg(distinct f1 order by f1::text) from varchar_tbl; -- not ok
+LINE 1: select string_agg(distinct f1::text, ',' order by f1) from v...
+ ^
+select string_agg(distinct f1, ',' order by f1::text) from varchar_tbl; -- not ok
ERROR: in an aggregate with DISTINCT, ORDER BY expressions must appear in argument list
-LINE 1: select string_agg(distinct f1 order by f1::text) from varcha...
- ^
-select string_agg(distinct f1::text order by f1::text) from varchar_tbl; -- ok
+LINE 1: select string_agg(distinct f1, ',' order by f1::text) from v...
+ ^
+select string_agg(distinct f1::text, ',' order by f1::text) from varchar_tbl; -- ok
string_agg
------------
- aababcd
+ a,ab,abcd
(1 row)
diff --git a/src/test/regress/expected/opr_sanity.out b/src/test/regress/expected/opr_sanity.out
index 5e36d481dfb..f6fee25de55 100644
--- a/src/test/regress/expected/opr_sanity.out
+++ b/src/test/regress/expected/opr_sanity.out
@@ -773,6 +773,31 @@ ORDER BY 1, 2;
min | < | 1
(2 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
diff --git a/src/test/regress/sql/aggregates.sql b/src/test/regress/sql/aggregates.sql
index b2199d1ce94..8f81ba763a0 100644
--- a/src/test/regress/sql/aggregates.sql
+++ b/src/test/regress/sql/aggregates.sql
@@ -357,14 +357,13 @@ select aggfns(distinct a,a,c order by a,b)
from (values (1,1,'foo')) v(a,b,c), generate_series(1,2) i;
-- string_agg tests
-select string_agg(a) from (values('aaaa'),('bbbb'),('cccc')) g(a);
select string_agg(a,',') from (values('aaaa'),('bbbb'),('cccc')) g(a);
select string_agg(a,',') from (values('aaaa'),(null),('bbbb'),('cccc')) g(a);
-select string_agg(a,',') from (values(null),(null),('bbbb'),('cccc')) g(a);
+select string_agg(a,'AB') from (values(null),(null),('bbbb'),('cccc')) g(a);
select string_agg(a,',') from (values(null),(null)) g(a);
-- check some implicit casting cases, as per bug #5564
-select string_agg(distinct f1 order by f1) from varchar_tbl; -- ok
-select string_agg(distinct f1::text order by f1) from varchar_tbl; -- not ok
-select string_agg(distinct f1 order by f1::text) from varchar_tbl; -- not ok
-select string_agg(distinct f1::text order by f1::text) from varchar_tbl; -- ok
+select string_agg(distinct f1, ',' order by f1) from varchar_tbl; -- ok
+select string_agg(distinct f1::text, ',' order by f1) from varchar_tbl; -- not ok
+select string_agg(distinct f1, ',' order by f1::text) from varchar_tbl; -- not ok
+select string_agg(distinct f1::text, ',' order by f1::text) from varchar_tbl; -- ok
diff --git a/src/test/regress/sql/opr_sanity.sql b/src/test/regress/sql/opr_sanity.sql
index 38866c9a549..46ec24cca6f 100644
--- a/src/test/regress/sql/opr_sanity.sql
+++ b/src/test/regress/sql/opr_sanity.sql
@@ -621,6 +621,26 @@ WHERE a.aggfnoid = p.oid AND a.aggsortop = o.oid AND
amopmethod = (SELECT oid FROM pg_am WHERE amname = 'btree')
ORDER BY 1, 2;
+-- 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;
+
+-- 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;
+
-- **************** pg_opfamily ****************
-- Look for illegal values in pg_opfamily fields
--
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