Optimize Oracle 11g SQL*Plus connection for large remote SELECTs
Instead of the 11g client, you should use at least 12.2, because:


11g is outdated
12.2 has builtin support for generating CSV output (MARKUP), sqlplus -M "CSV ON" user/password@address
you can simply start 12.2 with the -fast option (-F[ast]), that sets (which you can set and tune further manually as well):



ARRAYSIZE = 100
LOBPREFETCH = 16384
PAGESIZE = 50000
ROWPREFETCH = 2
STATEMENTCACHE = 20