On 01/20/2016 03:29 PM, Johannes wrote:
I noticed transferring a large object or bytea data between client and
server takes a long time.
For example: An image with a real size of 11 MB could be read on server
side (explain analyze) in 81ms. Fine.
But on client side the result was completed after 6.7 seconds without
ssl compression and 4.5 seconds with ssl compression (both via 100MBit
ethernet).
SSL compression seems to be not a good idea anymore, since this had
become a security risk. Its still possible with pgadmin, but afaik not
with java/jdbc .
Are there any other solutions available to display my images in my
client application more quickly? Or are there planned improvements to
postgresql (transferring the real binary data)?
Best regards
Johannes
Yep, that's slow. The ssl compression is very odd if the image is jpeg'ish and
already compressed. If its a bitmap or uncompressed tif then its not so
surprising.
A few tests you could try:
1) copy the same 11 meg file from server to client via regular file copy and
time it. At 100 Mbit/s it should take about a second. If it takes 6 you have
network problems, not PG problems.
2) try it via psql command line (or at least something other than java), to see
if its java thats the problem.
3) watch wireshark/tcpdump, maybe you'll see something glaring that'll point
you in the right direction.
-Andy
PS: I've never heard that ssl compression was a security risk, got links/proof?
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