Hi Adam,

Thank you for your reply.

Just one more question, what do you think about my Option 2)? Because
we can not see a BLOB field without a tool to retrive it first, then
open the mail in outlook.

regards,
Duncan

--- In firebird-support@yahoogroups.com, "Adam" <s3057043@y...> wrote:
> 3) Store the subject line (and possibly the message body) in a
> separate field from the attachments.
>
> In fact, have a separate table for the attachments altogether.
>
> EmailMessage
> (
> ID integer
> Sender Varchar([something])
> Subject Varchar([something]),
> OtherHeaders([something])
> Body Varchar([something])
> )
>
> EmailAttachment
> (
> ID integer,
> MessageID integer,
> AttachmentName VARCHAR([something]),
> AttachmentIcon BLOB
> Attachment BLOB
> )
>
> This means that you can efficiently get the name and Icon for each
> attachment and only download the attachment when they double click
> it. Alternatively, a background thread could retrieve the attachments
> for the current message into a local cache ready for when they are
> requested.
>
> I am not aware of the size limits for BLOBs (they are there but you
> are talking GB)
>
> As long as the text appears instantly, it will seem fast to the user.
> By the way, emails encode attachments generally in Base64, which is
> pathetically verbose (but necessary). You can compress the emails
> before storing them and the compression resource requirements will
> very quickly be offset by the over the wire savings.
>
>
> > 1) one is to save email in a blob field of the Firebird database.
> > 2) save email as .msg file, but keep the directory path in the
> database.
> >
> > For option 1), my concerns is the capacity, compatibility and
> > reliability of the BLOB field. What is the size limit of a blob
> field,
> > and can it store all different kind of attachments from emails, like
> > pictures and video clips?
>
> Apart from the max size limitation, BLOBs do not care what you put in
> them. They can not be indexed, and are stored uncompressed.
>
> Is there performance issue when retrieving
> > an email with large attachments?
>
> Of course. But this can be managed if the attachments and text are
> stored separately
>
> Adam