Re: memory usage

From: Tore Halset (halse..vv.ntnu.no)
Date: Tue Jan 31 2006 - 07:01:34 EST

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    On Jan 26, 2006, at 21:12, Andrus Adamchik wrote:

    > On Jan 26, 2006, at 2:55 PM, Tore Halset wrote:
    >
    >> On Apr 27, 2005, at 23:53, Andrus Adamchik wrote:
    >>
    >>> I was planning to add streaming blobs support, so that instead of
    >>> mapping
    >>> blob or clob as byte[] or String, you'd map it to a Cayenne-
    >>> provided class
    >>> that can provide a stream on demand. Don't remember if I ever
    >>> started a
    >>> task in Jira...
    >>>
    >>> In the meantoime you can imlement your own ExtendedType
    >>> (http://objectstyle.org/cayenne/userguide/access-stack/extended-
    >>> types.html)
    >>> that resolves LOBs on demand and doesn't store them in memory.
    >>
    >> I have tried this, but is it possible? Are fetched Blob-objects
    >> supposed to work after the ResultSet are closed?
    >>
    >> - Tore.
    >
    > It is true that most (all?) implementations returned by the JDBC
    > drivers won't work after ResultSet/Statement closing. However you
    > can implement a Blob (or a similar custom class/interface) that
    > stores an ObjectId and a DataContext and obtains a JDBC Blob on
    > demand when the caller requests an InputStream.

    Sorry for beeing extremly slow.

    Thanks for the tip, but does the ExtendedType instance know about the
    DataContext and ObjectId?

      - Tore.

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