Re: varchar and spaces problem..

don't store trail blank in varchar column.

You should recompile postgresql
There is only tiny change in "src/backend/utils/adt/varchar.c"
****************************************************************
Datum
varcharin(PG_FUNCTION_ARGS)
{
char *s = PG_GETARG_CSTRING(0);

#ifdef NOT_USED
Oid typelem = PG_GETARG_OID(1);
#endif
int32 atttypmod = PG_GETARG_INT32(2);
VarChar *result;
size_t len,
maxlen;

char *ermsg;

len = strlen(s);

if ((ermsg = pg_verifymbstr(s, len)))
elog(ERROR, "%s", ermsg);

maxlen = atttypmod - VARHDRSZ;

if (atttypmod >= (int32) VARHDRSZ && len > maxlen)
{
/* Verify that extra characters are spaces, and clip them off */
size_t mbmaxlen = pg_mbcharcliplen(s, len, maxlen);

if (strspn(s + mbmaxlen, " ") == len - mbmaxlen)
len = mbmaxlen;
else
elog(ERROR, "value too long for type character varying(%d)",
(int) maxlen);
}

/* **** don't save trail space char */

while (len > 0)
{
if (*(s + len - 1) != ' ')
break;
len--;
}
/* **** end */

result = palloc(len + VARHDRSZ);
VARATT_SIZEP(result) = len + VARHDRSZ;
memcpy(VARDATA(result), s, len);

#ifdef CYR_RECODE
convertstr(VARDATA(result), len, 0);
#endif

PG_RETURN_VARCHAR_P(result);
}

********************************************************
After all, YOU should migrate you previous data!
UPDATE TABLE SET VARCHAR_COL=TRIM(VARCHAR_COL,' ')