On Tue, Nov 08, 2011 at 04:59:02PM +0100, Albe Laurenz wrote:
> Tom Lane wrote:
> > There might be some argument for providing a client option to disable
> > compression, but it should not be forced, and it shouldn't even be the
> > default. But before adding YA connection option, I'd want to see some
> > evidence that it's useful over non-local connections.
>
> Here are numbers from a test via LAN.
> The client machine has OpenSSL 0.9.8e, the server OpenSSL 1.0.0.
>
> The client command run was
>
> echo 'select ...' | time psql "host=..." -o /dev/null
>
> and \timing was turned on in .psqlrc
>
> In addition to the oprofile data I collected three times:
> - the duration as shown in the server log
> - the duration as shown by \timing
> - the duration of the psql command as measured by "time"
>
> Without patch:
>
> duration: 5730.996 ms (log), 5975.093 ms (\timing), 22.87 s (time)
>
> samples % image name symbol name
> 4428 80.2029 libz.so.1.2.3 /lib64/libz.so.1.2.3
> 559 10.1250 postgres hex_encode
> 361 6.5387 libcrypto.so.1.0.0 /usr/lib64/libcrypto.so.1.0.0
> 83 1.5034 libc-2.12.so memcpy
>
> With patch:
>
> duration: 3001.009 ms (log), 3243.690 ms (\timing), 20.27 s (time)
>
> samples % image name symbol name
> 1072 58.0401 libcrypto.so.1.0.0 /usr/lib64/libcrypto.so.1.0.0
> 587 31.7813 postgres hex_encode
> 105 5.6849 libc-2.12.so memcpy
>
>
> I think this makes a good case for disabling compression.
>
> Yours,
> Laurenz Albe
Certainly a good case for providing the option to disable compression.
Regards,
Ken