Hi Nick Johnson Thank you for the perfect and prompt answer. :)
I never thought that 2^64 (1.84467441E19) is *so* huge! Thanks Jagan On Mon, Oct 11, 2010 at 8:52 PM, Nick Johnson (Google) < [email protected]> wrote: > 2010/10/11 Jaganathan (ஜ௧நாதன்) <[email protected]> > >> Hi >> >> In my app, I am using auto generated numeric ids. But for every new object >> they ids are stepping thru with a lot of gaps. >> >> Note that all the entities are root entities. >> >> With such stepping, I am really afraid of how many objects I can have at >> max per entity. Also, for many entities, the key id starts from very large >> number rather than 1001. >> >> Here is a sample data, for each entity type: >> >> *Note*: 1001, 4002, 5002, 6003, 9001, 9002, 9004, 13001, ...., 700002, >> 706002, 708002, 711001, 712001, 720001, 725001 >> *Node*: 2001, 4005, 5005, 6002, 8002, ....., 690002, 696001, 696003, >> 697004, 699003, 723001 >> *NoatUser*: 3001, 9005, 16002, 26001, 26002, 30002, ....., 601002, >> 601006, 603002, 620001, 622001, 706001 >> *Feedback*: 360006, 387007, 390006, 391003, 400007, 427002, 429001, >> 726001 >> *FeatureVoteUserDetails*: 325020, 327035, 454011, 454012, 455008, 466010, >> 485015, 491013, 495011, 497007 >> >> Questions / Doubts: >> >> 1. Is this much gap in entity id assignments fine and acceptable in App >>> Engine? >>> >> >> > > Yes. IDs are guaranteed to be unique, not sequential or contiguous. > > >> >>> >>>> 2. As numeric id is of 64 bits, one the id hits the limit of 2^64 (or >>>> 2^63 ??), will App Engine cycle back from the beginning, this time using >>>> the >>>> left over ids that it stepped thru?? >>>> >>> >>> >> > > If you generate or skip over a hundred million IDs per second, it will take > you nearly 6000 years to consume all 2^64 available IDs. Let us know when > you're getting close and we'll take care of it. ;) > > -Nick Johnson > > > >> Thanks >> Jagan >> > > -- > Nick Johnson, Developer Programs Engineer, App Engine Google Ireland Ltd. > :: Registered in Dublin, Ireland, Registration Number: 368047 > 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.
