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Roger Binns wrote:
> As a guess should I perhaps also order my documents so that the value
> emitted in a view (in most cases one value always from a key named "name")
> is also in sorted order?  With some SQL magic during document generation
> should be able to do that.

So I did that.  The resulting view file is 15GB (was 27GB) and took 43
minutes to generate (was 75 minutes).  Disk utilization started at 3% and
climbed to 10% at the end (was 30%).  couchjs remained at ~25% cpu
consumption and CouchDB was typically at 100% of one core (was around 110%).

The obvious conclusion is the append only file format for views is a really
bad thing.  As a format it is very good for data integrity but not efficient
for performance or size.

I do care about integrity of my documents, but the thing I care most about
for my views is performance.  (The major reason for a view is that it is
more performant than visiting every document.)  Losing data from a view is
no big deal - it can be regenerated (assuming generation doesn't remain as
slow as it is today :-).

Consequently I'd suggest using a different file format for views that is
space and performance oriented, and the only data integrity feature being
the ability to tell if some or all of it is inconsistent (eg if there was
abrupt shutdown).

Roger
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