Re: LOB-insert performance: is 25secs for 10Mb okay ?

André Hartmann wrote:

>>Do the math:
>>10MB/25 secs == 4MB/sec == 40Mbps
>
>
> uh ? what math's is that ? 10MB = 10*8 Mbit = 80Mbit. Rate: 80Mbit / 25sec
> = 3.2Mbps, at least with my calculator...
>

Oops - brain shut down without notification...

>
>>That is _without_ taking in consideration any overhead
>>regarding setting up network connections (how's your
>>DNS performing?!?), opening threads, opening file(s),
>>buffering (how large is your LOB buffer?), TCP overhead,
>
>
> client side lob buffering is not enabled. is there a server side lob
> buffering ?
>

AFAIK, you'll use a variable to hold a piece of the data, and append it to the LOB - loop until all data processed. What's the size of that variable? Something along the line of: WHILE length_count <> 0 LOOP

   dbms_lob.read (temp_blob, amount, position, data_buffer);    temp_buffer := utl_raw.cast_to_varchar2(data_buffer);

>Perhaps you can work out how long
>>the actual transfer takes? E.g. by sinking it to
>>/dev/null?
>
>
> i am on windows. no /dev/null there, right ? what do you mean ? should i
> compare a simple filesystem-to-filesystem copy to get an idea how much of
> the performance is taken by tcp/ip, ports, hard disks ? I tried that. A file
> of 18MB copies from one computer to the other in 3 secs, so that's roughly
> 48Mbps.

Well, that's useful info, but I thought more along the line of:

- prepare client side (open files)
- prepare network
- write time marker
- transfer
- write time marker

No need to actually _save_ the data... Anyway, your copy shows it must be possible to do it faster...

Sorry for the brain outage...

-- 

Regards,
Frank van Bortel