How to retrieve data from SQLite faster in python

I have the following info in my database (example):

longitude (str): 70.74
userid (str): 12

This is how i fetch it:

import sqlite3 as lite
con = lite.connect(dbpath)
    with con:
    cur = con.cursor()
    cur.execute('SELECT latitude, userid FROM message')
    con.commit()
    print "executed"
    while True:
        tmp = cur.fetchone()
        if tmp != None:
            info.append([float(tmp[0]),int(tmp[1])])
        else:
            break

To get the same info on the form [70.74, 12] I'm aware that I should save the latitude and userid as real (to conserve any leading zeros), not string - but what else can I do to speed up this process, as the number of values that are being read is quite high?