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From Alexander Shorin <kxe...@gmail.com>
Subject Re: Why are temp views so much faster than design docs?
Date Wed, 11 Feb 2015 10:18:56 GMT
On Wed, Feb 11, 2015 at 12:43 PM, Kiril Stankov <kiril@open-net.biz> wrote:
>
> Is there are problem to have all views in one doc, or one should spread them
> across several docs - what are the guidelines here?
> Does it affects how the btree is built?
> Any impact on the Compact?

There is no much problem for having a lot of views in single ddoc.
Problems starts when you need to change one or add/remove some from
ddoc. Then CouchDB will rebuild all the views in the ddoc, even those
you didn't touch.

As for btree, it allows to deduplicate map functions result. Say, you
need to apply different reduce functions onto the same map function.
You'll create two views with the same maps and different reduces. On
disk, only one map result will be stored.

On other hand, while having one-view-per-ddoc looks more flexible, it
will cause CouchDB to use more file descriptors, less effective
operate with file system cache.

Guidelines? It depends. Personally, I prefer to group views/design
functions by target document type or group of documents which they
operates with.

Here few more link on wiki about:
https://wiki.apache.org/couchdb/Why%20are%20all%20Views%20in%20a%20single%20Index
https://wiki.apache.org/couchdb/How_to_deploy_view_changes_in_a_live_environment

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,,,^..^,,,

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