а вы дальше проверьте уже не только на создании, но и на pg_bench:
pgbench -U postgres -j 32 -c 32 -M prepared -T 600 pgbench
:/home/user$ time pgbench -j 32 -c 32 -M prepared -T 600 pgbench
starting vacuum...end.
transaction type: <builtin: TPC-B (sort of)>
scaling factor: 1000
query mode: prepared
number of clients: 32
number of threads: 32
duration: 600 s
number of transactions actually processed: 1425678
latency average = 13.469 ms
tps = 2375.790120 (including connections establishing)
tps = 2376.012756 (excluding connections establishing)
real 10m0,334s
user 1m59,212s
sys 3m48,208s
postgres@u2004:/home/user$ time pgbench -j 32 -c 32 -M prepared -T 600 pgbench
starting vacuum...end.
transaction type: <builtin: TPC-B (sort of)>
scaling factor: 1000
query mode: prepared
number of clients: 32
number of threads: 32
duration: 600 s
number of transactions actually processed: 1056430
latency average = 18.178 ms
tps = 1760.353143 (including connections establishing)
tps = 1760.467637 (excluding connections establishing)
real 10m0,289s
user 1m34,845s
sys 3m13,124s