benchmark for postgres inserts using copy_from and IteratorFile from https://gist.github.com/jsheedy/ed81cdf18190183b3b7d

pg_copy_from.py

import time

import psycopg2

from iter_file import IteratorFile

conn = psycopg2.connect(host="localhost", database="test")

# args = [(1,2), (3,4), (5,6)]
args = [(i,i+1) for i in range(1,1*10**4,2)]

def time_test(func):
    def f():
        truncate_table()
        t1 = time.time()
        func()
        t2 = time.time()
        print(str(t2 - t1) + ": " + func.__name__ )
    return f

def truncate_table():
    with conn.cursor() as cur:
        cur.execute("truncate t");
        conn.commit()

@time_test
def query_builder_insert():
    with conn.cursor() as cur:
        records_list_template = ','.join(['%s'] * len(args))
        insert_query = 'insert into t (a, b) values {0}'.format(records_list_template)
        cur.execute(insert_query, args)
        conn.commit()

@time_test
def copy_from_insert():
    with conn.cursor() as cur:
        f = IteratorFile(("{}\t{}".format(x[0], x[1]) for x in args))
        cur.copy_from(f, 't', columns=('a', 'b'))
        conn.commit()

query_builder_insert()
copy_from_insert()

results.txt

# original
0.008857011795043945: query_builder_insert
0.0029380321502685547: copy_from_insert

#  10 records
0.00867605209350586: query_builder_insert
0.003248929977416992: copy_from_insert

# 10k records
0.041108131408691406: query_builder_insert
0.010066032409667969: copy_from_insert

# 1M records
3.464181900024414: query_builder_insert
0.47070908546447754: copy_from_insert

# 10M records
38.96936798095703: query_builder_insert
5.955034017562866: copy_from_insert