Query Read Performance
I don't know why Vertica send data slowly!
(I mean when it processed query and want to send it to output)
for example when i run my query (on vertica machine, 1 node), after 2nd second it start to write to file but it tacks about 120 seconds for writing a 1GB file (10M records).
it means about 8MBps!
(it was same when i queried 1M records to file)
i was suspicious of disk limit for writing, i wrote the vsql output on ramdisk but it was same
and also i switched to receiving output remotely but it consumed only about 12% of 1Gbps interface!
how can i find what is the bottleneck?
how can i improve it?