On Thu, 2020-07-30 at 19:16 +0200, Tomas Vondra wrote:
> > Essentially:
> > initHyperLogLog(&hll, 5)
> > for i in 0 .. one billion
> >addHyperLogLog(&hll, hash(i))
> > estimateHyperLogLog
> >
> > The numbers are the same regardless of bwidth.
> >
> > Before my patch, it takes about 15.6s.
On Thu, Jul 30, 2020 at 09:21:23AM -0700, Jeff Davis wrote:
On Wed, 2020-07-29 at 17:32 -0700, Peter Geoghegan wrote:
How did you test this? What kind of difference are we talking about?
Essentially:
initHyperLogLog(&hll, 5)
for i in 0 .. one billion
addHyperLogLog(&hll, hash(i))
estimat
On Wed, 2020-07-29 at 17:32 -0700, Peter Geoghegan wrote:
> How did you test this? What kind of difference are we talking about?
Essentially:
initHyperLogLog(&hll, 5)
for i in 0 .. one billion
addHyperLogLog(&hll, hash(i))
estimateHyperLogLog
The numbers are the same regardless of bwidt
On Wed, Jul 29, 2020 at 10:08 AM Jeff Davis wrote:
> Is there a reason that HyperLogLog doesn't use pg_leftmost_one_pos32()?
Yes: HyperLogLog predates pg_leftmost_one_pos32().
> I tried the following patch and some brief performance tests seem to
> show an improvement.
Makes sense.
How did you
