Thanks for the response!
On Dec 15, 12:01 am, 风笑雪 <kea...@gmail.com> wrote: > Calculating MD5 is very fast in GAE: > > from time import time > from hashlib import md5 > > s = '1'*100 > t = time() > for i in xrange(1000000): > md5(s).digest() > print time() - t > > result: 1.4655559063 > > I remember the key name is limited to 500 bytes long, so it may exceed if > you combine several keys into one. > > ---------- > keakon > > My blog(Chinese):www.keakon.net > Blog source code:https://bitbucket.org/keakon/doodle/ > > > > > > > > On Wed, Dec 15, 2010 at 2:43 PM, johnP <j...@thinkwave.com> wrote: > > I need to create a large amount of records which relate three other > > entities. Just for example, take 100 people; 100 days; and 100 > > restaurants. To create a record for an intersection of a person/day/ > > restaurant, it's possible to create keyname of person.key()+day.key() > > +restaurant.key(). And to retrieve records, it's easy to generate a > > list of keys and use a db.get(). > > > In the internet somewhere, I read a comment by Nick Johnson saying > > that long keynames are inefficient, and that it can be a good idea to > > use a MD5 or SHA1 hash function to shorten the key name. My question > > is, how expensive are the MD5 and SHA1 functions? > > > For example, if I need to generate 100 keys for each view (e.g. to > > retrieve people who visited 1 restaurant in 1 day, I can generate 100 > > keys and db.get() that list) - is it cheaper to use the MD5 hash to > > keep key_names shorter? Or is the cost of generating the hashes more > > than any savings from shortening the keys? > > > -- > > You received this message because you are subscribed to the Google Groups > > "Google App Engine" group. > > To post to this group, send email to google-appeng...@googlegroups.com. > > To unsubscribe from this group, send email to > > google-appengine+unsubscr...@googlegroups.com<google-appengine%2Bunsubscrib > > e...@googlegroups.com> > > . > > For more options, visit this group at > >http://groups.google.com/group/google-appengine?hl=en. -- You received this message because you are subscribed to the Google Groups "Google App Engine" group. To post to this group, send email to google-appeng...@googlegroups.com. To unsubscribe from this group, send email to google-appengine+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/google-appengine?hl=en.
