Subject Re: [firebird-support] Re: Store Blobs in Seperate Tables?
Author Lester Caine
Ann W. Harrison wrote:

> Just for the sake of absolute and pedantic correctness, updating (or
> inserting or deleting) a record doesn't put a "lock" on it. These
> operations create a new version of the record (the first, in the case of
> inserts) which carries the transaction id of the transaction that
> created the version. Thus a single record that had been updated four
> times would have five versions, each with the transaction id of the
> transaction that created it.

And to complete the picture - since the BLOB is handled in the table as
a link, all the data in the blob will not be copied until you actually
make a change to the BLOB itself. That is if my understanding is
correct. So when handling large volumes of data BLOB's are more
efficient than VARCHAR fields which would be duplicated on every copy
even if not changed.

Is that a fair summary ?

Lester Caine
L.S.Caine Electronic Services