cx oracle python example query large table

import cx_Oracle
import time
import pandas

user = "test"
pw = "test"
dsn="localhost:port/TEST"

con = cx_Oracle.connect(user,pw,dsn)
start = time.time()
cur = con.cursor()
cur.arraysize = 10000
try:
    cur.execute( "select * from test_table" )
    names = [ x[0] for x in cur.description]
    rows = cur.fetchall()
    df=pandas.DataFrame( rows, columns=names)
    print(df.shape)
    print(df.head())
finally:
    if cur is not None:
        cur.close()

elapsed = (time.time() - start)
print(elapsed, "seconds")