Обсуждение: Wrong length of bytea field

I inserted two binary files to a bytea field "contents"

file1  size was 7834649 bytes
file2 size was 5888534 bytes

select filename,
octet_length(contents),
length(contents)
from localfil

returns

"file1                              ";16777184;16777184
"file2                              ";15768893;15768893

It seems that for some reason postgres returns sometimes escaped string size
(eq. single byte 0x00 uploaded as \\000 size is returned as 5 )

Why result is incorrect ?
How to get the actual size of bytea field ?

Using Postgres 8.1 in XP , cluster encoding is UTF-8

Andrus.

On Fri, Feb 24, 2006 at 10:32:58PM +0200, Andrus Moor wrote:
> It seems that for some reason postgres returns sometimes escaped string size
> (eq. single byte 0x00 uploaded as \\000 size is returned as 5 )

I'd guess that "some reason" is because the data was over-escaped
when it was inserted -- that is, escaped and then escaped again.
Try inserting a small file and querying for the bytea column and
see what you get.

CREATE TABLE foo (data bytea);

INSERT INTO foo VALUES ($$\000$$);
INSERT INTO foo VALUES ($$\\000$$);
INSERT INTO foo VALUES ($$\\\000$$);
INSERT INTO foo VALUES ($$\\\\000$$);

SELECT data, octet_length(data) FROM foo;
  data   | octet_length
---------+--------------
 \000    |            1
 \\000   |            4
 \\\000  |            2
 \\\\000 |            5
(4 rows)

--
Michael Fuhr