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Home > Archive > PostgreSQL JDBC > July 2005 > Re: Streaming blob to db
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Re: Streaming blob to db
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| Kris Jurka 2005-07-04, 7:23 am |
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On Fri, 1 Jul 2005, [UTF-8] æ^Y^Bæ^\^_ ç²¾é^\Š wrote:
>
> I got a web application that use jdbc and that will need to stream
> binary data to the database.
>
> My application need an outputstream to send the data to the db, and
> an inputstream to read the data from the db.
>
> I use postgresql 8.0.1 with bytea field.
>
>
If you are really dealing with 100+Mb files you should probably look into
using large objects instead of bytea storage. This will provide the
streaming interfaces you are looking for and avoid excessive memory usage.
http://jdbc.postgresql.org/document...inary-data.html
Kris Jurka
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| 時期 精霊 2005-07-05, 7:23 am |
| How can I trigger the deletion of the large object when the row
containing the oid is deleted?
I mean I know that:
DELETE FROM pg_largeobject WHERE loid = nnn
But is there in jdbc, an automatic way to handle that?
Regards
Kuon
On Jul 4, 2005, at 11:33 AM, Kris Jurka wrote:
>
>
> On Fri, 1 Jul 2005, [UTF-8] æ^Y^Bæ^\^_ ç²¾é^\Š wrote:
>
>
> If you are really dealing with 100+Mb files you should probably
> look into
> using large objects instead of bytea storage. This will provide the
> streaming interfaces you are looking for and avoid excessive memory
> usage.
>
> http://jdbc.postgresql.org/document...inary-data.html
>
> Kris Jurka
>
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| Roland Walter 2005-07-05, 9:24 am |
| 時期 精霊 schrieb:
> How can I trigger the deletion of the large object when the row
> containing the oid is deleted?
>
> I mean I know that:
> DELETE FROM pg_largeobject WHERE loid = nnn
>
> But is there in jdbc, an automatic way to handle that?
>
There is a vacuumlo program in the contrib directory of the
database source. If the contributed programs are installed you
should have it. The readme for it is usually installed in
the directory doc/contrib in the directory of the database installation.
--
Roland Walter phone: +49 (0) 22 25 / 88 2-41 1
MOSAIC SOFTWARE AG fax: +49 (0) 22 25 / 88 2-20 1
Am Pannacker 3 mailto: rwa (at) mosaic-ag (dot) com
D-53340 Meckenheim http://www.mosaic-ag.com
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| Tom Lane 2005-07-05, 9:24 am |
| Roland Walter <rwa@mosaic-ag.com> writes:
> 時期 精霊 schrieb:
[color=darkred]
> There is a vacuumlo program in the contrib directory of the
> database source.
Also see contrib/lo for a trigger you can install to delete blobs
immediately when the reference is deleted.
regards, tom lane
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