Select 100k rows using Psycopg2

select100k_psycopg2.py

import psycopg2
import psycopg2.extras
import sys
import time

conn = None

class Generic:
    pass

try:
    conn = psycopg2.connect("host='localhost' dbname='test' user='postgres' password='password'")
    
    cur = conn.cursor(cursor_factory = psycopg2.extras.DictCursor)
    sql = "select a,b,c,d,e from table1"
    
    start = time.time()
    cur.execute(sql)
    res = cur.fetchall()
    elapsed = time.time() - start
    print('query time: ' + str(elapsed * 1000))
    
    start = time.time()
    rowlist = []
    for r in res:
        g = Generic()
        g.a = r['a']
        g.b = r['b']
        g.c = r['c']
        g.d = r['d']
        g.e = r['e']
        rowlist.append(g)
    elapsed = time.time() - start
    print('conversion time: ' + str(elapsed * 1000))
    
    print('res size: ' + str(sys.getsizeof(res)))
    print('rowlist size: ' + str(sys.getsizeof(rowlist)))
        
except Exception, err:
    print('error')
    print(err)
    
finally:
    if conn is not None: conn.close()