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From: Jens Alfke <jens@couchbase.com>
To: "user@couchdb.apache.org" <user@couchdb.apache.org>
Date: Fri, 7 Oct 2011 21:39:54 -0700
Subject: Re: How does the B-tree for view indexes behave?
Thread-Topic: How does the B-tree for view indexes behave?
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On Oct 7, 2011, at 6:59 PM, Pulkit Singhal wrote:

1) Does CouchDB mark existing rows in a view index as "invalid" for ALL of
the following operations: add,delete, edit?

Yes.

2) For deletes: Is the info not added at the end of the B-tree for the view
index?

I=92m not sure what you mean by =93at the end=94. See below.

3) Does CouchDB break out of its "append-only-model" if a document gets
updated for a view index? Are the resulting new lines really inserted into
the B-tree? Why the change in behavior?

You=92re mixing up two layers of abstraction: the b-tree itself, where we c=
an talk about operations like =93insertion=94 and =93deletion=94; and the f=
ile format, which is strictly append-only.

So yes, changes do get inserted into or deleted from the b-tree. But at the=
 file level, those operations are implemented only through appending to the=
 file.

=97Jens

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