Re: OCTET_LENGTH is wrong

> I think "the value of S" implies "the user-accessible representation of
> the value of S", in the sense, "How much memory do I need to allocate to
> store this value".
>
> Furthermore, the size of the TOAST representation that is returned now is
> just one particular of several intermediate representations.  For
> instance, it does not include the VARHDRSZ and it does not include the
> size of the tuple headers when it's stored externally.  Thus, this size is
> heavily skewed toward low numbers and doesn't tell you much about either
> the disk end or the user's end.

Yes, good arguments.  If we want to implement storage_length at some
later time, I think the compressed length may be appropriate, but for
general use, I think we need to return the uncompressed length,
especially considering that multibyte makes the ordinary 2length return
number of characters, so users need a way to get byte length.

Attached is a patch that makes text return the same value type as char()
and varchar() already do.  As Tatsuo pointed out, they were
inconsistent.  All the other octet_length() functions look fine so it
was only text that had this problem.

--
  Bruce Momjian                        |  http://candle.pha.pa.us
  pgman@candle.pha.pa.us               |  (610) 853-3000
  +  If your life is a hard drive,     |  830 Blythe Avenue
  +  Christ can be your backup.        |  Drexel Hill, Pennsylvania 19026
Index: src/backend/utils/adt/varlena.c
===================================================================
RCS file: /cvsroot/pgsql/src/backend/utils/adt/varlena.c,v
retrieving revision 1.74
diff -c -r1.74 varlena.c
*** src/backend/utils/adt/varlena.c    2001/10/25 05:49:46    1.74
--- src/backend/utils/adt/varlena.c    2001/11/18 19:11:52
***************
*** 273,284 ****
  Datum
  textoctetlen(PG_FUNCTION_ARGS)
  {
!     struct varattrib *t = (struct varattrib *) PG_GETARG_RAW_VARLENA_P(0);

!     if (!VARATT_IS_EXTERNAL(t))
!         PG_RETURN_INT32(VARATT_SIZE(t) - VARHDRSZ);
!
!     PG_RETURN_INT32(t->va_content.va_external.va_extsize);
  }

  /*
--- 273,281 ----
  Datum
  textoctetlen(PG_FUNCTION_ARGS)
  {
!     text    *arg = PG_GETARG_VARCHAR_P(0);

!     PG_RETURN_INT32(VARSIZE(arg) - VARHDRSZ);
  }

  /*