Hi Jagan,

On Tue, Aug 31, 2010 at 9:46 AM, Jagan <[email protected]> wrote:

> Hi Google, Nick Johnson and others
>
> Does Google recommend using UUID (UUID4 to be specific) as key names
> for entities in GAE instead of auto generated numeric ids?
>
> Does this hold good in all use cases in the universe?
>

This depends entirely on your use-case. Unless you expect an extremely high
insertion rate of new entities (eg, >=100QPS) with no natural key name, it's
not necessary to use a UUID. UUIDs take more space than regular integer IDs.


>
> And is this the reason why import export of auto generates IDs are not
> yet supported in BulkUpload? Should I wait till this is supported or
> should I refactor my code to use UUID key names?
>

It's possible to do this using the bulkloader, but requires you to override
a method to generate key names.


>
> Is there a demo page that compares between the bulk read/write
> performance between entities that have 32-bit numeric ids versus xxx-
> bit UUID key names?
>

The performance should be roughly the same - but the space used will be
significantly larger in the case of UUIDs.

-Nick Johnson


>
> Some home work that I did:
>
>
> http://groups.google.com/group/google-appengine/browse_thread/thread/bc868376ffa37619/db9bda21c95ea806?lnk=gst&q=uuid#db9bda21c95ea806
>
>
> http://groups.google.com/group/google-appengine/browse_thread/thread/a6fcce84837c34b/d4c9d5b3c7869222?lnk=gst&q=uuid#d4c9d5b3c7869222
>
>
> http://groups.google.com/group/google-appengine/browse_thread/thread/7dedb7d65bdf4f/37f2733fd9f572b9?lnk=gst&q=uuid#37f2733fd9f572b9
>
> Thanks
> Jagan
>
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-- 
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

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