On 2019/03/21 17:27, David Steele wrote:
Hi Hironobu,
Sorry for the late reply. I reviewed this patch.
Function nbits(), which was previously discussed, has been simplified by
using the function pg_popcount64().
By adding the mathematical explanation, it has been easier to understand
the operation of this function.
I believe that these improvements will have a positive impact on
maintenance.
The patch could be applied successfully and the tests passed without
problems.
So, I think the latest patch is fine.
Best regards,
On 3/3/19 12:55 PM, Fabien COELHO wrote:
Indeed, the patch needs a rebase & conflit resolution. I'll do it.
Later.
Here is an update:
- take advantage of pg_bitutils (although I noted that the "slow"
popcount there could be speeded-up and shorten with a bitwise
operator
implementation that I just removed from pgbench).
- add comments about the bijective transformations in the code.
As already stated, this function makes sense for people who want to
test performance with pgbench using non uniform rands. If you do not
want to do that, you will probably find the function pretty useless. I
can't help it.
Also, non uniform rands is also a way to test pg lock contention
behavior.
You have signed up as a reviewer for this patch. Do you know when
you'll have time to do the review?
Regards,
