Hi Adam, thanks for taking an interest in this.

Btw., I also created this as a jira issue at:
https://issues.apache.org/jira/browse/COUCHDB-700

> Henrik, thanks for this cogent and detailed analysis.  I was aware that the 
> 0.11 work queues introduced significantly more checkpoints and thus larger 
> uncompacted view index files in the normal case where writes to the view 
> indices are fast.  I was not aware that this slowed down overall view 
> generation time; I had always sort of assumed that the queues would make 
> optimal use of resources.  How many cores do you have on your benchmark rig?

Well, these things should really be measured :-). Actually 0.11 writes
A LOT to more disk. More I/O almost always means slower. And
unfortunately keeping resources busy is not the same as optimal usage.
The scheme also has the unintentional effect that faster I/O systems
can do more writes thereby using more space.

I've used my laptop for benchmarking. It has 2 cores.

> It's probably too late to add this simple patch to 0.11, but I'm sure 
> something like it will be in 1.0 (which should follow shortly on the heels of 
> 0.11).  Best,

The patch I submitted is really only a simple stopgap; though it works
fairly well. A proper fix it to better control the disk-writeouts.
0.10 had this fairly right with the batch_save_size and
batch_save_interval options (which no longer affects views in 0.11).


   best regards, Henrik

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