Subject Re: Performance Problem with BOLBs??
Author ggroper
Pete,

My weakest Link is my cable modem, fast download but slower upload. I
believe I read that it's around 150kb upload and 500kb download??

For 3,000 charcters this can not account for the Blob performace
problem. (2 sec local and 30 second remote??)

Is Firbird requesting every blob separately and waits to request the
next blob after it receives the first, thus sending 35 separate read
requests like running 35 queries - so it takes about a second for a
turn around?? Why so fast local and so slow remote??

Austin




--- In firebird-support@yahoogroups.com, "Pete Bray" <pete@s...> wrote:
> > However, for my test app returning 35 records in less than 2 seconds
> > with NO Blobs and 32 seconds with blobs conataing a total 3,209 plain
> > text characters does not make sense?? Especially, when all get
> > returned very fast on a local connection.
> >
> > Does anyone have any ideas??
>
> how 'asymetric' is your wan connection at the weakest point. i
didn't get
> the expected performance benefit moving from varchar to blob (this
was pre
> firebird 1.5 which now has over the wire compression for varchar)
and i'm
> pretty sure it was due to the increase in packet handshaking
required to get
> a blob (they will be so many people on this list better able to
comment on
> this but i think that a record is returned containing the id of the
blob and
> then the client goes and requests the actual blob using the id). if
you have
> a slow upstream link this would slow down the data download because
> presumably each blob has to be requested.
>
> just an idea.....
>
> pete