Thanks for the explanation Aaron!
Renato M.
2013/1/15 Aaron Turner <synfina...@gmail.com>:
> The timestamp is the time the record was inserted into the Cassandra
> node. It's used for conflict resolution, so if two clients insert
> different data into the same row/column, Cassandra can pick the
> "winner" (most recent timestamp).
>
> You can set it manually on insert, otherwise the node will pick the
> current time for you (this is a major reason why you want all your
> Cassandra nodes clocks synchronized via NTP by the way). It's also
> available to be read, but I don't recall any API available (Hector or
> otherwise) which allows you to search based on the timestamp value.
>
> On Tue, Jan 15, 2013 at 11:51 AM, Renato Marroquín Mogrovejo
> <renatoj.marroq...@gmail.com> wrote:
>> Hi Aaron,
>>
>> Thanks for answering! Yeah that is what I did but then when looking
>> into the actual column family created I saw this timestamp column
>> which Cassandra had created. Are we allowed to use this? What is this
>> specifically for?
>> Thanks again for the help!
>>
>>
>> Renato M.
>>
>> 2013/1/15 Aaron Turner <synfina...@gmail.com>:
>>> I don't think so. Usually you'd use either a Time-UUID or something
>>> like epoch time as the column name to get a range of columns by time
>>> range.
>>>
>>> On Tue, Jan 15, 2013 at 10:46 AM, Renato Marroquín Mogrovejo
>>> <renatoj.marroq...@gmail.com> wrote:
>>>> Hi all,
>>>>
>>>> I am having some problems while retrieving some events from a column
>>>> family I have created.
>>>> My column family has been created as follows:
>>>>
>>>> create column family click_event
>>>> WITH comparator = UTF8Type and
>>>> column_metadata = [ {column_name: event, validation_class: UTF8Type} ];
>>>>
>>>> My table is populated as follows:
>>>>
>>>> list click_events;
>>>> -------------------
>>>> => (column=start:2013-01-13 18:14:59.244, value=,
>>>> timestamp=1358118943979000)
>>>> => (column=stop:2013-01-13 18:15:56.793,
>>>> value=323031332d30312d31332031383a31353a35382e333437,
>>>> timestamp=1358118960946000)
>>>>
>>>> I have two questions here:
>>>> 1) What is the timestamp column used for?
>>>> 2) How can I retrieve this timestamp column using Hector client?
>>>>
>>>> Thanks in advance!
>>>>
>>>>
>>>> Renato M.
>>>
>>>
>>>
>>> --
>>> Aaron Turner
>>> http://synfin.net/ Twitter: @synfinatic
>>> http://tcpreplay.synfin.net/ - Pcap editing and replay tools for Unix &
>>> Windows
>>> Those who would give up essential Liberty, to purchase a little temporary
>>> Safety, deserve neither Liberty nor Safety.
>>> -- Benjamin Franklin
>>> "carpe diem quam minimum credula postero"
>
>
>
> --
> Aaron Turner
> http://synfin.net/ Twitter: @synfinatic
> http://tcpreplay.synfin.net/ - Pcap editing and replay tools for Unix &
> Windows
> Those who would give up essential Liberty, to purchase a little temporary
> Safety, deserve neither Liberty nor Safety.
> -- Benjamin Franklin
> "carpe diem quam minimum credula postero"
