Subject Re: [IBO] Files "Blobed" or "Linked"?
Author Daniel Rail

At Wednesday, March 12, 2008, 2:53 PM, skander_sp wrote:

> I need to store some documentation in a FB database...
> I'm thinking use BLOB row to do.... but I read in diferents post abot
> "DO NOT BLOB, use links"
> But REALLY is so dangerous to do? slow REALLY down the database working?

> I read about it, and supossed the blob fields are stored in separated
> pages, and only read under request... that is not slow down the work,
> index and other works... only grow up the size (of course).

> I think store inside is better because I can take more control about
> the use, and no one can "rename, modify or delete" from the directori
> where I can store it I link. And if the backup is full -not
> incremental- I think even better because Im sure the backup is do,
> even if someone is reading a field at the moment.

> Any REAL pros or contras?

> Anyone is using the blob fields for store a big ammount of files?

We store the files in blobs and we don't have any issues. When it's
in the blob, the user doesn't have to have another link to the server
where the files would be. And, as you said, what happens if someone
changes the filename directly in the folder?

The systems that we developed that stores the files into blobs are
currently handling several thousand files and those files can range
from a few kilobytes to a few megabytes, with the biggest database
that we know of is currently managing over 10GB worth of files inside
the database. And, there's no slowdown in retrieval from the database.

That being said, there is a difference in the performance compared to
retrieving a blob compared to retrieving a file from a file server.
But, if the fastest performance is not that important, save the files
inside blobs for more convenience. And, we are always trying to save
the file zipped within a blob, so that it doesn't take too much space
in the database and is smaller when transferring from the database.

Best regards,
Daniel Rail
Senior Software Developer
ACCRA Solutions Inc. (
ACCRA Med Software Inc. (