From e292dbcf543183fa6eae98c377b3939d08794676 Mon Sep 17 00:00:00 2001
From: Peter Eisentraut <peter_e@gmx.net>
Date: Tue, 7 Jul 2009 18:23:15 +0000
Subject: [PATCH] More sensible character_octet_length
For character types with typmod, character_octet_length columns in the
information schema now show the maximum character length times the
maximum length of a character in the server encoding, instead of some
huge value as before.
---
doc/src/sgml/information_schema.sgml | 23 +++++++++++-----------
src/backend/catalog/information_schema.sql | 7 +++++--
src/backend/utils/mb/mbutils.c | 13 +++++++++++-
src/include/catalog/catversion.h | 4 ++--
src/include/catalog/pg_proc.h | 5 ++++-
src/include/utils/builtins.h | 3 ++-
6 files changed, 37 insertions(+), 18 deletions(-)
diff --git a/doc/src/sgml/information_schema.sgml b/doc/src/sgml/information_schema.sgml
index b6e143c5da5..78346d422d5 100644
--- a/doc/src/sgml/information_schema.sgml
+++ b/doc/src/sgml/information_schema.sgml
@@ -1,4 +1,4 @@
-<!-- $PostgreSQL: pgsql/doc/src/sgml/information_schema.sgml,v 1.39 2009/06/10 07:03:34 petere Exp $ -->
+<!-- $PostgreSQL: pgsql/doc/src/sgml/information_schema.sgml,v 1.40 2009/07/07 18:23:13 petere Exp $ -->
<chapter id="information-schema">
<title>The Information Schema</title>
@@ -343,10 +343,10 @@
<entry><type>cardinal_number</type></entry>
<entry>
If <literal>data_type</literal> identifies a character type,
- the maximum possible length in octets (bytes) of a datum (this
- should not be of concern to
- <productname>PostgreSQL</productname> users); null for all
- other data types.
+ the maximum possible length in octets (bytes) of a datum; null
+ for all other data types. The maximum octet length depends on
+ the declared character maximum length (see above) and the
+ server encoding.
</entry>
</row>
@@ -947,9 +947,10 @@
<entry><type>cardinal_number</type></entry>
<entry>
If <literal>data_type</literal> identifies a character type,
- the maximum possible length in octets (bytes) of a datum (this
- should not be of concern to <productname>PostgreSQL</productname> users); null for all
- other data types.
+ the maximum possible length in octets (bytes) of a datum; null
+ for all other data types. The maximum octet length depends on
+ the declared character maximum length (see above) and the
+ server encoding.
</entry>
</row>
@@ -1688,9 +1689,9 @@
<entry><type>cardinal_number</type></entry>
<entry>
If the domain has a character type, the maximum possible length
- in octets (bytes) of a datum (this should not be of concern to
- <productname>PostgreSQL</productname> users); null for all
- other data types.
+ in octets (bytes) of a datum; null for all other data types.
+ The maximum octet length depends on the declared character
+ maximum length (see above) and the server encoding.
</entry>
</row>
diff --git a/src/backend/catalog/information_schema.sql b/src/backend/catalog/information_schema.sql
index b295abbeab5..946d1bc8eaf 100644
--- a/src/backend/catalog/information_schema.sql
+++ b/src/backend/catalog/information_schema.sql
@@ -4,7 +4,7 @@
*
* Copyright (c) 2003-2009, PostgreSQL Global Development Group
*
- * $PostgreSQL: pgsql/src/backend/catalog/information_schema.sql,v 1.54 2009/06/10 07:03:34 petere Exp $
+ * $PostgreSQL: pgsql/src/backend/catalog/information_schema.sql,v 1.55 2009/07/07 18:23:13 petere Exp $
*/
/*
@@ -104,7 +104,10 @@ CREATE FUNCTION _pg_char_octet_length(typid oid, typmod int4) RETURNS integer
AS
$$SELECT
CASE WHEN $1 IN (25, 1042, 1043) /* text, char, varchar */
- THEN CAST(2^30 AS integer)
+ THEN CASE WHEN $2 = -1 /* default typmod */
+ THEN CAST(2^30 AS integer)
+ ELSE information_schema._pg_char_max_length($1, $2) * pg_catalog.pg_encoding_max_length((SELECT encoding FROM pg_database WHERE datname = current_database()))
+ END
ELSE null
END$$;
diff --git a/src/backend/utils/mb/mbutils.c b/src/backend/utils/mb/mbutils.c
index 9a739019531..fe8941b3c02 100644
--- a/src/backend/utils/mb/mbutils.c
+++ b/src/backend/utils/mb/mbutils.c
@@ -4,7 +4,7 @@
*
* Tatsuo Ishii
*
- * $PostgreSQL: pgsql/src/backend/utils/mb/mbutils.c,v 1.87 2009/06/11 14:49:05 momjian Exp $
+ * $PostgreSQL: pgsql/src/backend/utils/mb/mbutils.c,v 1.88 2009/07/07 18:23:14 petere Exp $
*/
#include "postgres.h"
@@ -482,6 +482,17 @@ length_in_encoding(PG_FUNCTION_ARGS)
}
+Datum
+pg_encoding_max_length_sql(PG_FUNCTION_ARGS)
+{
+ int encoding = PG_GETARG_INT32(0);
+
+ if (PG_VALID_ENCODING(encoding))
+ return pg_wchar_table[encoding].maxmblen;
+ else
+ PG_RETURN_NULL();
+}
+
/*
* convert client encoding to server encoding.
*/
diff --git a/src/include/catalog/catversion.h b/src/include/catalog/catversion.h
index dcd149d0513..ef7f3927879 100644
--- a/src/include/catalog/catversion.h
+++ b/src/include/catalog/catversion.h
@@ -37,7 +37,7 @@
* Portions Copyright (c) 1996-2009, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
- * $PostgreSQL: pgsql/src/include/catalog/catversion.h,v 1.531 2009/06/11 14:49:09 momjian Exp $
+ * $PostgreSQL: pgsql/src/include/catalog/catversion.h,v 1.532 2009/07/07 18:23:14 petere Exp $
*
*-------------------------------------------------------------------------
*/
@@ -53,6 +53,6 @@
*/
/* yyyymmddN */
-#define CATALOG_VERSION_NO 200904091
+#define CATALOG_VERSION_NO 200907071
#endif
diff --git a/src/include/catalog/pg_proc.h b/src/include/catalog/pg_proc.h
index d71623e6672..9c13ea3c494 100644
--- a/src/include/catalog/pg_proc.h
+++ b/src/include/catalog/pg_proc.h
@@ -7,7 +7,7 @@
* Portions Copyright (c) 1996-2009, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
- * $PostgreSQL: pgsql/src/include/catalog/pg_proc.h,v 1.544 2009/06/11 14:49:09 momjian Exp $
+ * $PostgreSQL: pgsql/src/include/catalog/pg_proc.h,v 1.545 2009/07/07 18:23:14 petere Exp $
*
* NOTES
* The script catalog/genbki.sh reads this file and generates .bki
@@ -2278,6 +2278,9 @@ DESCR("convert encoding name to encoding id");
DATA(insert OID = 1597 ( pg_encoding_to_char PGNSP PGUID 12 1 0 0 f f f t f s 1 0 19 "23" _null_ _null_ _null_ _null_ PG_encoding_to_char _null_ _null_ _null_ ));
DESCR("convert encoding id to encoding name");
+DATA(insert OID = 2319 ( pg_encoding_max_length PGNSP PGUID 12 1 0 0 f f f t f i 1 0 23 "23" _null_ _null_ _null_ _null_ pg_encoding_max_length_sql _null_ _null_ _null_ ));
+DESCR("maximum octet length of a character in an eocidng");
+
DATA(insert OID = 1638 ( oidgt PGNSP PGUID 12 1 0 0 f f f t f i 2 0 16 "26 26" _null_ _null_ _null_ _null_ oidgt _null_ _null_ _null_ ));
DESCR("greater-than");
DATA(insert OID = 1639 ( oidge PGNSP PGUID 12 1 0 0 f f f t f i 2 0 16 "26 26" _null_ _null_ _null_ _null_ oidge _null_ _null_ _null_ ));
diff --git a/src/include/utils/builtins.h b/src/include/utils/builtins.h
index 06d8e04d1d6..de9adb87b34 100644
--- a/src/include/utils/builtins.h
+++ b/src/include/utils/builtins.h
@@ -7,7 +7,7 @@
* Portions Copyright (c) 1996-2009, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
- * $PostgreSQL: pgsql/src/include/utils/builtins.h,v 1.332 2009/03/09 14:34:34 petere Exp $
+ * $PostgreSQL: pgsql/src/include/utils/builtins.h,v 1.333 2009/07/07 18:23:15 petere Exp $
*
*-------------------------------------------------------------------------
*/
@@ -948,6 +948,7 @@ extern Datum pg_convert(PG_FUNCTION_ARGS);
extern Datum pg_convert_to(PG_FUNCTION_ARGS);
extern Datum pg_convert_from(PG_FUNCTION_ARGS);
extern Datum length_in_encoding(PG_FUNCTION_ARGS);
+extern Datum pg_encoding_max_length_sql(PG_FUNCTION_ARGS);
/* format_type.c */
extern Datum format_type(PG_FUNCTION_ARGS);
--
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