Re: Streaming binary data into db, difference between Blob - Mailing list pgsql-jdbc

That sounds like really good idea.

Just we can't map to bytea cause it is specific to Postgres, but I would
definitely put this on the feature list for c-jdbc.

Thanks a lot for that.

Nicolas,

On Wed, 2003-09-10 at 16:14, Dave Tenny wrote:
> You could always implement your own logical blob manager that
> implements blob IDs
> and breaks blobs into BYTEA records of a particular (manageable)
> maximum size and associates
> multiple BYTEA chunks with the blob id.
>
> More work, but a least common denominator approach that should be
> portable to other systems as well.
>
> Nicolas Modrzyk wrote:
> > I was following the conversation on blobs with interest.
> >
> > c-jdbc supports Blobs and Binaries with Postgres.
> > At the moment though, given the number of different platforms we are
> > trying to support there is no streaming as such available.
> >
> > But you can definitely stored and retrieve Blobs from your postgres
> > databases environment with redundancy.
> >
> > Nicolas,
> >
> >
> > On Wed, 2003-09-10 at 15:32, Andreas Prohaska wrote:
> >
> > > > > Looking at the AbstractJdbc2Blob class I think that JDBC Blobs
> > > > >
> > >
> > > internally
> > >
> > > > > use LargeObjects. As I know, this was not the case in earlier versions
> > > > > of the driver. Am I right?
> > > > >
> > > > >
> > > >
> > > > This is for the PostgreSQL Large Objects, not the standard JDBC and SQL
> > > > BLOBs.
> > > >
> > > >
> > >
> > > OK. If I got you right, the Postgres JDBC driver "simulates" the
> > > java.sql.Blob
> > > getBinaryStream() etc. methods by using LargeObject internally.
> > >
> > > That seems to be a working solution for me. I just want to keep my
> > > application's
> > > database layer compatible using ordinary JDBC objects. I don't mind if
> > > they are mapped to LargeObject internally. Actually that's even better
> > > regarding
> > > the streaming issues :-)
> > >
> > > I assume that I can use this to read and write Blobs, not to delete them
> > > since the LargeObject wouldn't be unlinked.
> > >
> > > I'm not familiar with the JDBC driver source, and I would be glad if you
> > > could
> > > confirm this just one more time.
> > >
> > >
> > > > > So far, I'm using LargeObjects and everything works fine,  but I intend
> > > > >
> > >
> > > to
> > >
> > > > > use c-jdbc for db replication and would have to use JDBC blobs then.
> > > > >
> > > > >
> > > >
> > > > We don't have them yet because PostgreSQL does not have them.  But I
> > > > believe c-jdbc works with PostgreSQL so there must be a way around it.
> > > >
> > >
> > > It certainly works with Postgres, the only question is if it works with
> > > blobs?
> > > I'll try it out.
> > >
> > > Thanks for your help,
> > >
> > >     Andreas
> > >
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