Re: Using blobs and Cayenne

From: Tore Halset (halse..vv.ntnu.no)
Date: Thu Sep 21 2006 - 03:21:55 EDT

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    Hello.

    Cayenne currently handles blob/clob as any other property. They are
    working, but there are no streaming support and the cache will be
    filled with blobs. This is handled by the following feature request:

    http://issues.apache.org/cayenne/browse/CAY-316

    In my main project, the blobs are never bigger than 5MB. I currently
    do not use cayenne for this blob column as I am afraid that the cache
    will be filled up.

    PostgreSQL has different types of clob/blob columns. Make sure you
    pick the correct one. I am using oid instead of bytea for my blob
    columns as oid support streaming.

    OT Comment about psql and blobs: The downside of using oid as blob
    column in PostgreSQL is that getObject (jdbc) returns Integer instead
    of Blob. getBlob works. This is a problem with Sequoia as it uses
    getObject :( . The postgresql-jdbc-guys are not able to make this
    work as "oid" are used for other things than blobs as well.

      - Tore.

    On Sep 20, 2006, at 0:18, Eric Lazarus wrote:

    > Hi, Folks!
    >
    > We are happy and up and running again.
    >
    > Question: We have text were were thinking we would
    > store on a file system on the webserver and just keep
    > the name of the file in the database.
    >
    > These files may be as large as a million characters.
    >
    > Would we be wise to use a clob field or to stay with
    > what has been working for us, i.e., just storing the
    > files as files to the database?
    >
    > I like the transactional nature of storing things in
    > the database but I don't know what other problems we
    > might be getting ourselves into by storing such data
    > in the database.
    >
    > We use Postgresql under Linux with TomCat.
    >
    > We are concerned, for example, that we will not find
    > it easy to backup the database or that other issues,
    > not nec. cayenne related my mess us up.
    >
    > Thanks!
    >
    > Eric
    > +1 (917) 589-6579
    >
    > __________________________________________________
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