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From Michael Genereux <mgene...@gmail.com>
Subject Re: Pruning a couchdb database
Date Sat, 02 Oct 2010 16:29:32 GMT
The problem I have had with rotating databases is that statistics are
harder to gather.  Let's say one database has an average of $50 profit
per widget sold and the other database has an average of $30 profit
per widget sold, you can't just add 50 and 30 and divide by two to get
the profit over two months.  The reason I use CouchDB is to make
getting realtime statistics easier.

On Mon, Sep 27, 2010 at 5:38 PM, Chris Anderson <jchris@apache.org> wrote:
> On Mon, Sep 27, 2010 at 8:36 AM, Simon Metson
> <simonmetson@googlemail.com> wrote:
>> Hi John,
>>        How about having the date in the database name e.g:
>>
>> johns_database/Sept2010
>> johns_database/Oct2010
>>
>> Pruning then becomes a case of dropping the database en masse, e.g. to kill
>> all records in a certain time window.
>>
>> That said, pulling out a view and doing a bulk delete shouldn't be too slow.
>> Also, don't forget to compact the database after you delete records from it!
>
> For your use case, rotating databases is much better. Deletes still
> linger in the database file (so they can replicate) so the case of
> deleting old records won't reclaim 100% of the space. There is a purge
> command for truly removing records, but I think the rotating db files
> is much simpler.
>
> Chris
>
>> Cheers
>> Simon
>>
>> On 27 Sep 2010, at 16:26, John Logsdon wrote:
>>
>>> Hi
>>>
>>> I need to hold, potentially, millions of call records in a couchdb cluster
>>> and using a management process periodically truncate the records based on
>>> their age. I can see how I can get the Set of matching records using a
>>> View
>>> but how do I delete them in the same operation? My understanding is that I
>>> can only GET from a View so I cant see how to do this without bringing the
>>> data back to the client and issuing a DELETE for each record which would
>>> be
>>> a real problem wrt performance.
>>>
>>> Regards
>>>
>>> John
>>
>>
>
>
>
> --
> Chris Anderson
> http://jchrisa.net
> http://couch.io
>

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