Hi All, Every identifier is downcase & truncated by function "downcase_truncate_identifier()" before using it.
But since the function "downcase_truncate_identifier()" is not
multibyte-charecter aware,
it is not able to downcase some of special charecters in identifier like
"my_SchemÄ".
If schema is created of name "my_SchemÄ", pg_namespace shows entries as
"my_schemÄ" .
Example is as below :
postgres=# create schema my_SchemÄ;
CREATE SCHEMA
postgres=# select nspname from pg_namespace;
nspname
--------------------
pg_toast
pg_temp_1
pg_toast_temp_1
pg_catalog
public
information_schema
my_schemÄ
(7 rows)
postgres=#
Achually it should downcase as "my_schemä" as per multibyte-character aware
as lower()
works :
postgres=# select lower('my_SchemÄ');
lower
-----------
my_schemä
(1 row)
There is function str_tolower() which work as multibyte-character aware.
Need to use same function where ever downcase required. So, it will create
uniform down-casing at all places.
two places identified where need to add wide-character aware downcase :
1. downcase_truncate_identifier();
- Attaching patch for changes and small test case.
Following functions should also synchronise with
"downcase_truncate_identifier()" :
2. pg_strcasecmp();
3. pg_strncasecmp();
- to add fix at these functions (2,3) need to move str_tolower() from
formatting.c from backend to some common location (may be in src/port) from
where these can be used with client as well as server.
Thanks & Regards,
Rajanikant Chirmade.
diff --git a/orig/postgresql-9.0beta2/src/backend/parser/scansup.c b/postgresql-9.0beta2/src/backend/parser/scansup.c
index 94082f7..179b37e 100644
--- a/orig/postgresql-9.0beta2/src/backend/parser/scansup.c
+++ b/postgresql-9.0beta2/src/backend/parser/scansup.c
@@ -129,33 +129,11 @@ char *
downcase_truncate_identifier(const char *ident, int len, bool warn)
{
char *result;
- int i;
-
- result = palloc(len + 1);
-
- /*
- * SQL99 specifies Unicode-aware case normalization, which we don't yet
- * have the infrastructure for. Instead we use tolower() to provide a
- * locale-aware translation. However, there are some locales where this
- * is not right either (eg, Turkish may do strange things with 'i' and
- * 'I'). Our current compromise is to use tolower() for characters with
- * the high bit set, and use an ASCII-only downcasing for 7-bit
- * characters.
- */
- for (i = 0; i < len; i++)
- {
- unsigned char ch = (unsigned char) ident[i];
- if (ch >= 'A' && ch <= 'Z')
- ch += 'a' - 'A';
- else if (IS_HIGHBIT_SET(ch) && isupper(ch))
- ch = tolower(ch);
- result[i] = (char) ch;
- }
- result[i] = '\0';
+ result = str_tolower(ident, len);
- if (i >= NAMEDATALEN)
- truncate_identifier(result, i, warn);
+ if (len >= NAMEDATALEN)
+ truncate_identifier(result, len, warn);
return result;
}
--- This tests if identifier with special charecters using wide-charecter aware downcase.
create schema my_SchemÄ;
--- Since we smash identifiers to lower we try to find schema name
--- by downcasing nspname.
select count(nspname) from pg_namespace where nspname=LOWER('my_SchemÄ');
drop schema my_SchemÄ;
wide-charecter_aware_downcase.out
Description: Binary data
-- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
