Indeed.. I didn't notice any change either (when changing segment size).
However, like I said before, I noticed an awfull lot of packets going over
and back with very little data.

I hope not that's the best optimization the wire protocol can come up with
:-)

Anyway.. the blob's I'm storing aren't really that big or so.. It's mainly
HTML templates and variable user input.. so I figure the average on those
blobs stays under 2k. It's just that when I used the VarChar type, I read
somewhere that the server expands the varchar with spaces and then transfers
the whole thing.. I read that IBO then throws those spaces away again...
seems to me to be unnecessary transfer over the line.. I think/thought blobs
were more efficient... I could be wrong though..

-----Oorspronkelijk bericht-----
Van: Jason Wharton [mailto:jwharton@...]
Verzonden: woensdag 24 januari 2001 17:28
Aan: IBObjects@egroups.com
Onderwerp: Re: [IBO] Performance (as a result of blob inserts)


IBO ignores the segment size. I slam it up to 64Kb. Segments were an
artifact of living at a time when a system may not have had a spare 32K
laying around to buffer the contents of a large BLOB. Nowadays, 64Kb is not
a big deal...

I am assuming that the wire protocol will know how to most efficiently
package and transport the BLOB data no matter what the size of the segments
are declared as. I could be wrong here but I haven't noticed any performance
degradations in so doing.

FWIW,
Jason Wharton
CPS - Mesa AZ
http://www.ibobjects.com

----- Original Message -----
From: "Lucas Franzen" <luc@...>
To: <IBObjects@egroups.com>
Sent: Wednesday, January 24, 2001 4:20 AM
Subject: Re: [IBO] Performance (as a result of blob inserts)


>
>
> "ing. Thijs Kuperus" schrieb:
> >
> > Hello there,
> >
> > I keep shooting questions!
> >
> > Another one:
> >
> > What is the minimum line speed over which i can reasonably run IBO and
> > Interbase on a remote server? Perhaps my situation to illustrate:
> >
> > I have a server running on the internet. I connect to my ISP with single
> > ISDN (64KBit/s). The RTT (Round Trip Time) is between 60 and 200 ms...
Now I
> > noticed that for instance a blob insert can't go above 4 inserts a sec!
Upon
> > inspecting the line stats, I saw that for about each 80 bytes a packet
is
> > send... considering a TCP/IP overhead of about 50 bytes that means a
VERY
> > bad optimized connection.. on a LAN everything works just great, coz the
RTT
> > is very low, but when we're on the internet, those small packets really
hit
> > the performance hard...
> >
> > So... what do the experts say about this?
>
> It seems that you haven't defined the segment size for your blobs - if
> you don't do so then the default sgement size is 80.
>
> You can try to create another segment size and see which performs best.
>
> for example:
> create domain T_BLOB_1024 as BLOB SEGMENT SIZE 1024;
>
> Have a look in the Data Definiton Reference, page 71 ff. (DATADEF.PDF
> for IB 5.6)
>
> Let me know, if this will improve performance.
>
> Regrads
> Luc.
>
>
>