Re: md5(large_object_id)

2015-10-07 13:18 GMT+02:00 Karsten Hilbert <Karsten(dot)Hilbert(at)gmx(dot)net>:

> On Wed, Oct 07, 2015 at 12:55:38PM +0200, Karsten Hilbert wrote:
>
> > > > I am dealing with radiology studies aka DICOM data) one would
> > > > want an md5 function which streams in parts of a large object
> > > > piece by piece using md5_update and m5_finalize or some such.
> > > It would certainly be possible to write a lo_md5(oid) function to do
> > > this, but as far as I'm aware nobody has yet done so. How are your
> > > C skills?
> >
> > I had hoped someone was going to say: "Yeah, right, low
> > hanging fruit, let's just do it for 9.next" :-)
>
> Someone _with_ C skills, that is.
>

if the size of blobs is less than 1GB, then it should be possible in
plpgsql too.

postgres=# \lo_import ~/Desktop/001.jpg
lo_import 24577
postgres=# select md5(lo_get(24577));
┌──────────────────────────────────┐
│ md5 │
╞══════════════════════════════════╡
│ 610ccaab8c7c60e1168abfa799d1305d │
└──────────────────────────────────┘
(1 row)

Regards

Pavel

> Thanks for the plperlu suggestion, btw.
>
> Karsten
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