Hi Tom

I'm honestly not sure about anything. =) I use the exact same flags as with 8.4 
for the dump:

${BINARY_PATH}/pg_dump --host=localhost --user=postgres --no-password --blobs 
--format=custom --verbose --file=${pg_dump_filename}_${database}.backup 

So unless the default behaviour have changed in 9.x I'd say I don't use 
compression. I will try to force it to no compression and see if it's different.

Sadly the instruments session stopped recording when I logged out of the system 
yesterday. Doh. =/


Henrik Cednert
cto | compositor

Filmlance International
mobile [ + 46 (0)704 71 89 54 ]
skype  [ cednert ]

On 21 Nov 2017, at 22:01, Tom Lane 
<t...@sss.pgh.pa.us<mailto:t...@sss.pgh.pa.us>> wrote:

"Henrik Cednert (Filmlance)" 
<henrik.cedn...@filmlance.se<mailto:henrik.cedn...@filmlance.se>> writes:
I'm not sure if I can attach screenshots here. Trying, screenshot from 
instruments after running for a few mins.

It looks like practically all of pg_dump's time is going into deflate(),
ie zlib.  I don't find that terribly surprising in itself, but it offers
no explanation for why you'd see a slowdown --- zlib isn't even our
code, nor has it been under active development for a long time, so
presumably 8.4 and 9.5 would have used the same version.  Perhaps you
were doing the 8.4 dump without compression enabled?

regards, tom lane

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