> Hi List !
>
> Is it true that it is a bad idea to store BLOB's together with other
> fields in 1 table (performance) ? Is it better to store those fields
> in a seperate table ?

No. and No - not required - internally , blobs are stored on separate
database pages and the refernce to them is the only thing saved adjacent to
the other fields in the table.

>
> In case it is bad : is it only bad if that field is part of the SELECT
> statement ? Or is it also bad even if the field is not included in the
> SELECT ?

initial selects which include blobs do not retrieve the blob contents, they
just select the blob IDs.
This may be implemtation specific, however, since some components may not
follow this (i.e. they may retrieve blob contents at the same time)
standard.

>
> And last : What if there is no value given for the BLOB for a
> particular record, is the database assigning space for it anyway ?

no space is allocated until there is something to store in the blob.
Just remember that blob updates actually write a new copy of the blob into
the database, they don't adjust the previous version. This (old) space is
released under normal operations and is ready for re-use. Just remember also
that database filesize will never reduce until you do a backup/restore
cycle. This means that the file size doesn't always reflect the amount of
data stored in the DB. It just allows the server to use space quickly
without having to request it from the OS.

Alan

>
> Thanks a lot and best regards,
>
> Mary Ann
>
>
>
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