Subject Re: [firebird-support] Store large amount of Binary Data in FB
Author Ann W. Harrison
Teträm Corp wrote:
>>>> Is it advisable to store such huge binary data in FireBird?
>>> not really
>> Really? Why not?
> afair, storing as huge blob as Yogi Yang needs reduces FB1.5 (don't know
> for newer versions) performances (at least effectiveness of indexes)

That's very unlikely. I can think of two ways that blobs might
affect index performance: by decreasing record density and thus
increasing the number of reads necessary to read a range of records
from an index, and by allowing the creation of ineffective indexes
on blob data.

Blobs are stored separately from record data, on separate blob
pages when they are more than a page long, so they have little
impact on record density. Small blobs are stored on page so
they have the same effect as equivalent varchar fields ...
actually somewhat less since varchars store two bytes per 128
bytes of declared but unused length while the blob stores only
the used length.

Blobs aren't indexed, so the second problem is not an issue either.