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From Sylvain Lebresne <sylv...@yakaz.com>
Subject Re: Question about TimeUUIDType
Date Sat, 24 Apr 2010 09:08:02 GMT
On Sat, Apr 24, 2010 at 12:53 AM, Jesse McConnell
<jesse.mcconnell@gmail.com> wrote:
> try LexicalUUIDType, that will distinguish the secs correctly
>
> imo based on the existing impl (last I checked at least) TimeUUIDType
> was equivalent to LongType

It uses to be true that the TimeUUIDType comparator was only comparing the
timestamps of the UUIDs. But this was more a bug than anything else
since it made
different UUID collide and was fixed for 0.6
(https://issues.apache.org/jira/browse/CASSANDRA-907).

Now with TimeUUIDType, if two UUID have the same timestamps, they are ordered
by bytes order.

--
Sylvain


>
> cheers,
> jesse
>
> --
> jesse mcconnell
> jesse.mcconnell@gmail.com
>
>
>
> On Fri, Apr 23, 2010 at 17:51, Lucas Di Pentima <lucas@di-pentima.com.ar> wrote:
>> Hello,
>>
>> I'm using Cassandra 0.6.1 with ruby library
>>
>> I want to log events on a CF like this:
>>
>> Events = { // CF CompareWith: TimeUUIDType
>>    SomeEventID : { // Row
>>        uuid_from_unix_timestamp : event_data,
>>        ...
>>    }
>> }
>>
>> I receive event data with a UNIX timestamp (nr of seconds passed since some date
on 1970), so I would do something like:
>>
>> db = Cassandra.new('Keyspace')
>> db.insert('Events', SomeEventID, {SimpleUUID:UUID.new(Time.at(unix_timestamp)} =>
event_data)
>>
>> My first question was: What happens if I have more than one event at the same second?
I tried this on irb console and checked that TimeUUIDs are different.
>>
>> So, my second question is: How different TimeUUIDs generated from the same UNIX timestamp
are going to be ordered in the ColumnFamily?
>>
>> Thanks in advance!!
>> --
>> Lucas Di Pentima - Santa Fe, Argentina
>> Jabber: lucas@di-pentima.com.ar
>> MSN: ldipenti75@hotmail.com
>>
>>
>>
>>
>>
>

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