Re: Streaming binary data into db, difference between Blob

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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