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peterepetere
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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.
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6 files changed

+37
-18
lines changed

6 files changed

+37
-18
lines changed

‎doc/src/sgml/information_schema.sgml

Lines changed: 12 additions & 11 deletions
Original file line numberDiff line numberDiff line change
@@ -1,4 +1,4 @@
1-
<!-- $PostgreSQL: pgsql/doc/src/sgml/information_schema.sgml,v 1.39 2009/06/10 07:03:34 petere Exp $ -->
1+
<!-- $PostgreSQL: pgsql/doc/src/sgml/information_schema.sgml,v 1.40 2009/07/07 18:23:13 petere Exp $ -->
22

33
<chapter id="information-schema">
44
<title>The Information Schema</title>
@@ -343,10 +343,10 @@
343343
<entry><type>cardinal_number</type></entry>
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<entry>
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If <literal>data_type</literal> identifies a character type,
346-
the maximum possible length in octets (bytes) of a datum (this
347-
should not be of concern to
348-
<productname>PostgreSQL</productname> users); null for all
349-
other data types.
346+
the maximum possible length in octets (bytes) of a datum; null
347+
for all other data types. The maximum octet length depends on
348+
the declared character maximum length (see above) and the
349+
server encoding.
350350
</entry>
351351
</row>
352352

@@ -947,9 +947,10 @@
947947
<entry><type>cardinal_number</type></entry>
948948
<entry>
949949
If <literal>data_type</literal> identifies a character type,
950-
the maximum possible length in octets (bytes) of a datum (this
951-
should not be of concern to <productname>PostgreSQL</productname> users); null for all
952-
other data types.
950+
the maximum possible length in octets (bytes) of a datum; null
951+
for all other data types. The maximum octet length depends on
952+
the declared character maximum length (see above) and the
953+
server encoding.
953954
</entry>
954955
</row>
955956

@@ -1688,9 +1689,9 @@
16881689
<entry><type>cardinal_number</type></entry>
16891690
<entry>
16901691
If the domain has a character type, the maximum possible length
1691-
in octets (bytes) of a datum (this should not be of concern to
1692-
<productname>PostgreSQL</productname> users); null for all
1693-
other data types.
1692+
in octets (bytes) of a datum; null for all other data types.
1693+
The maximum octet length depends on the declared character
1694+
maximum length (see above) and the server encoding.
16941695
</entry>
16951696
</row>
16961697

‎src/backend/catalog/information_schema.sql

Lines changed: 5 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -4,7 +4,7 @@
44
*
55
* Copyright (c) 2003-2009, PostgreSQL Global Development Group
66
*
7-
* $PostgreSQL: pgsql/src/backend/catalog/information_schema.sql,v 1.54 2009/06/10 07:03:34 petere Exp $
7+
* $PostgreSQL: pgsql/src/backend/catalog/information_schema.sql,v 1.55 2009/07/07 18:23:13 petere Exp $
88
*/
99

1010
/*
@@ -104,7 +104,10 @@ CREATE FUNCTION _pg_char_octet_length(typid oid, typmod int4) RETURNS integer
104104
AS
105105
$$SELECT
106106
CASE WHEN $1 IN (25, 1042, 1043) /* text, char, varchar */
107-
THEN CAST(2^30 AS integer)
107+
THEN CASE WHEN $2 = -1 /* default typmod */
108+
THEN CAST(2^30 AS integer)
109+
ELSE information_schema._pg_char_max_length($1, $2) * pg_catalog.pg_encoding_max_length((SELECT encoding FROM pg_database WHERE datname = current_database()))
110+
END
108111
ELSE null
109112
END$$;
110113

‎src/backend/utils/mb/mbutils.c

Lines changed: 12 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -4,7 +4,7 @@
44
*
55
* Tatsuo Ishii
66
*
7-
* $PostgreSQL: pgsql/src/backend/utils/mb/mbutils.c,v 1.87 2009/06/11 14:49:05 momjian Exp $
7+
* $PostgreSQL: pgsql/src/backend/utils/mb/mbutils.c,v 1.88 2009/07/07 18:23:14 petere Exp $
88
*/
99
#include "postgres.h"
1010

@@ -482,6 +482,17 @@ length_in_encoding(PG_FUNCTION_ARGS)
482482

483483
}
484484

485+
Datum
486+
pg_encoding_max_length_sql(PG_FUNCTION_ARGS)
487+
{
488+
int encoding = PG_GETARG_INT32(0);
489+
490+
if (PG_VALID_ENCODING(encoding))
491+
return pg_wchar_table[encoding].maxmblen;
492+
else
493+
PG_RETURN_NULL();
494+
}
495+
485496
/*
486497
* convert client encoding to server encoding.
487498
*/

‎src/include/catalog/catversion.h

Lines changed: 2 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -37,7 +37,7 @@
3737
* Portions Copyright (c) 1996-2009, PostgreSQL Global Development Group
3838
* Portions Copyright (c) 1994, Regents of the University of California
3939
*
40-
* $PostgreSQL: pgsql/src/include/catalog/catversion.h,v 1.531 2009/06/11 14:49:09 momjian Exp $
40+
* $PostgreSQL: pgsql/src/include/catalog/catversion.h,v 1.532 2009/07/07 18:23:14 petere Exp $
4141
*
4242
*-------------------------------------------------------------------------
4343
*/
@@ -53,6 +53,6 @@
5353
*/
5454

5555
/* yyyymmddN */
56-
#define CATALOG_VERSION_NO 200904091
56+
#define CATALOG_VERSION_NO 200907071
5757

5858
#endif

‎src/include/catalog/pg_proc.h

Lines changed: 4 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -7,7 +7,7 @@
77
* Portions Copyright (c) 1996-2009, PostgreSQL Global Development Group
88
* Portions Copyright (c) 1994, Regents of the University of California
99
*
10-
* $PostgreSQL: pgsql/src/include/catalog/pg_proc.h,v 1.544 2009/06/11 14:49:09 momjian Exp $
10+
* $PostgreSQL: pgsql/src/include/catalog/pg_proc.h,v 1.545 2009/07/07 18:23:14 petere Exp $
1111
*
1212
* NOTES
1313
* The script catalog/genbki.sh reads this file and generates .bki
@@ -2278,6 +2278,9 @@ DESCR("convert encoding name to encoding id");
22782278
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_ ));
22792279
DESCR("convert encoding id to encoding name");
22802280

2281+
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_ ));
2282+
DESCR("maximum octet length of a character in an eocidng");
2283+
22812284
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_ ));
22822285
DESCR("greater-than");
22832286
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_ ));

‎src/include/utils/builtins.h

Lines changed: 2 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -7,7 +7,7 @@
77
* Portions Copyright (c) 1996-2009, PostgreSQL Global Development Group
88
* Portions Copyright (c) 1994, Regents of the University of California
99
*
10-
* $PostgreSQL: pgsql/src/include/utils/builtins.h,v 1.332 2009/03/09 14:34:34 petere Exp $
10+
* $PostgreSQL: pgsql/src/include/utils/builtins.h,v 1.333 2009/07/07 18:23:15 petere Exp $
1111
*
1212
*-------------------------------------------------------------------------
1313
*/
@@ -948,6 +948,7 @@ extern Datum pg_convert(PG_FUNCTION_ARGS);
948948
extern Datum pg_convert_to(PG_FUNCTION_ARGS);
949949
extern Datum pg_convert_from(PG_FUNCTION_ARGS);
950950
extern Datum length_in_encoding(PG_FUNCTION_ARGS);
951+
extern Datum pg_encoding_max_length_sql(PG_FUNCTION_ARGS);
951952

952953
/* format_type.c */
953954
extern Datum format_type(PG_FUNCTION_ARGS);

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