Just doing some research on this topic, and found this: http://www.eggheadcafe.com/software/aspnet/35761883/bookmarks-database-struct.aspx
"Encouragingly, if a 128bit MD5 hash is used, then even for ten billion bookmarks, there is only a 10^-18 chance of collison." The chance 10^-18 is good enough for me. On a side question, is there a prioritized list of top things to do to save bigtable space? >From reading the forums, I see: 1. Reduce key (name) length 2. Reduce attribute name length 3. Reduce kind name #1 can be handled by design, #2 #3 can be handled by tool I can mess with my JET (for POJO entity wrapper) to do some map attributes and kind to short names. However, is #2 #3 worth it? It will be annoying to use the datastore viewer with names like "a" "b" "c". IMO the most annoying part of optimizing space for GAE is that you have to do it from the beginning. Other optimizations you can do later when you know your app is hit and worth optimizing. Is optimizing bigtable space part of the GAE team agenda? Or is it by design to ensure maximum flexibility for the datastore? Thanks. On Mar 24, 8:06 am, "Nick Johnson (Google)" <[email protected]> wrote: > Hi Peter, > > On Wed, Mar 24, 2010 at 6:01 AM, Peter Liu <[email protected]> wrote: > > Is using url as a string key for an entity really inefficient for > > space? > > > Say if the url is long and it's 1k byte, each key is repeatedly stored > > with each indexed property right? If you have a list property of 5000 > > items, will the keys of those 5000 index entries consume 5M? > > That's correct (give or take some overhead factor). If you're concerned > about length, you might want to consider using the MD5 or SHA1 hash of the > URL as the key instead. > > -Nick Johnson > > > > > Thanks. > > > -- > > You received this message because you are subscribed to the Google Groups > > "Google App Engine" group. > > To post to this group, send email to [email protected]. > > To unsubscribe from this group, send email to > > [email protected]<google-appengine%[email protected]> > > . > > For more options, visit this group at > >http://groups.google.com/group/google-appengine?hl=en. > > -- > Nick Johnson, Developer Programs Engineer, App Engine > Google Ireland Ltd. :: Registered in Dublin, Ireland, Registration Number: > 368047 -- You received this message because you are subscribed to the Google Groups "Google App Engine" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/google-appengine?hl=en.
