Re: Store (large) images inside or outside database?
Re: Store (large) images inside or outside database?
- Subject: Re: Store (large) images inside or outside database?
- From: Andrew Lindesay <email@hidden>
- Date: Fri, 8 Feb 2008 23:41:28 +1300
Hello Susanne;
I have a project where I'm needing to store fairly large quantities of
data as files - maybe some hundreds of gigs or a terabyte or so. I
keep an index of the data in a relational database, but the actual
files are stored on a file-server. I have written a little servlet
file-server running off Jetty-6 for the WebObjects application server
to be able to easily read and write the file-server without mounting
any drives. The system has the capacity to stream the data from the
file server disc, through the servlet, through WO and to the client
without ending up entirely in memory. This approach has worked well
for me so far, but I don't think the system has needed shifted 100 MB
in one file.
I also use BLOBs in another system. I have written a BLOB streaming
system (see my framework) where the storage is broken into a large
number of BLOBs. As it streams, the sequence of BLOBs are loaded and
added to the input stream and then garbage collected. This has
advantages in some situations, but I think would be less appropriate
for what you are doing.
cheers.
today I need some advice on a conceptual basis:
We need to include images in our WO 5.2.3 application working
with Oracle 9.i as a database. The images may be of various kind
including DICOM images and therefore could be very different in size
(maybe from 100 KB up to 100 MB or even more).
Besides the problem of handling such variety of formats I could not
really make up my mind if we should store such large objects in the
database and reflect them with eo-properties or store them in the
filesystem and only the pointer in the database. The images are
treated
as read only: once they were uploaded they will be stored and only be
displayed for download/view. The image property would be put into a
separate table to be only loaded if needed. It is not possible to
put the images under webserver-control because they include
sensitive information.
These were my considerations:
- memory consumption while using eos (as I understood the image-
property
would at least be hold twice: once in the eo in every editing context
and once in the snapshot)
- backup and recovery issues of the database
- transaction management
Any comments?
___
Andrew Lindesay
technology : www.lindesay.co.nz
business : www.silvereye.co.nz
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