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From Robert Newson <rnew...@apache.org>
Subject Re: Considering CouchDB
Date Wed, 20 Nov 2013 22:57:25 GMT
The bigcouch merge will not bring any automatic view updating
scheduler. Nothing stops someone contributing one, of course.

B.


On 20 November 2013 22:49, Mike Marino <mmarino@gmail.com> wrote:
> There are, of course, ways to get couchdb to update views dependent on
> writes. I also believe this is supposed to get easier in the future
> (included in the bigcouch merge?).
>
>> Am 20.11.2013 um 23:46 schrieb Simon Metson <simon@cloudant.com>:
>>
>> Nope, views are updated on read, hence the "blocking" behaviour you describe. You
can query with update_after, which returns the stale index then triggers the update.
>>
>>
>>> On Wednesday, 20 November 2013 at 22:43, Mark Hahn wrote:
>>>
>>> I thought that every write triggered a view rebuild and that the stale
>>> option only meant a read didn't have to wait for a current rebuild to
>>> finish. That would means the views are pretty much up-to-date.
>>>
>>>
>>>> On Wed, Nov 20, 2013 at 2:36 PM, Robert Newson <rnewson@apache.org>
wrote:
>>>>
>>>> True, but remember couchdb doesn't automatically keep indexes fresh in
>>>> the background, so "stale" can be "really really stale". ;)
>>>>
>>>> B.
>>>>
>>>>
>>>>> On 20 November 2013 22:34, Simon Metson <simon@cloudant.com> wrote:
>>>>> Unless your app can deal with querying the view stale.
>>>>>
>>>>>
>>>>>> On Wednesday, 20 November 2013 at 21:56, Mark Hahn wrote:
>>>>>>
>>>>>> I meant http view requests were blocked. It is waiting for the view
>>>>>> rebuild.
>>>>>>
>>>>>> I'm can't type what I'm thinking today.
>>>>>>
>>>>>>
>>>>>>> On Wed, Nov 20, 2013 at 1:54 PM, Mark Hahn <mark@reevuit.com>
wrote:
>>>>>>>
>>>>>>> never mind. I wasn't talking about the file level at all. I meant
that
>>>>>>> http read requests are blocked after http update requests.
>>>>>>>
>>>>>>>
>>>>>>> On Wed, Nov 20, 2013 at 1:52 PM, Robert Newson <rnewson@apache.org>
>>>> wrote:
>>>>>>>
>>>>>>>> "DB reads are blocked by DB updates at the http level."
>>>>>>>>
>>>>>>>> Nope, there's a process that can read the database and a
separate
>>>> one
>>>>>>>> for writing to it. Writing to an append only file is obviously
>>>>>>>> serialized but there's no need to block reads.
>>>>>>>>
>>>>>>>> B.
>>>>>>>>
>>>>>>>>
>>>>>>>> On 20 November 2013 21:35, Mark Hahn <mark@reevuit.com>
wrote:
>>>>>>>>>> Database writes are not coupled to view updates.
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> I understand now, you are talking about file read/write
level. DB
>>>> reads
>>>>>>>>> are blocked by DB updates at the http level.
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> On Wed, Nov 20, 2013 at 1:05 PM, Robert Newson <
>>>> robert.newson@gmail.com
>>>>>>>>> wrote:
>>>>>>>>>
>>>>>>>>>> "A write requires updating views and reads have to
wait for the
>>>> update"
>>>>>>>>>>
>>>>>>>>>> Is not true. Database writes are not coupled to view
updates.
>>>>>>>>>>
>>>>>>>>>> Sent from my iPad
>>>>>>>>>>
>>>>>>>>>>> On 20 Nov 2013, at 20:59, Mark Hahn <mark@reevuit.com>
wrote:
>>>>>>>>>>>
>>>>>>>>>>> A write requires updating views and reads have
>>>>>>>>>>> to wait for the update
>>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>
>>>>>>>>
>>>>>>>
>>>>>>
>>>>>
>>>>
>>>>
>>>
>>>
>>>
>>
>>

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