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Re: 2.1 & 2.2 statistics, and some odd behavior that needs to be examined.

> Any thoughts on why 'file-backed DB caching' is causing such a problem
> under 2.2 as compared to 2.1?

Isn't it that 2.2 has higher write overhead than 2.1 and hence the 'shared memory DB
has higher impact than the 'file-backed DB caching' on their performances ?
Assuming no swapping, continuous writes to a shared memory region can be performed without
access, while writes to the named memory mapping can cause writeback of dirty pages if the
of dirty pages goes beyond a threshold. Since slapadding produces a lot of dirty pages,
disk write activities would be observed with the 'file-backed DB caching'.
- Jong