Re: Abbreviated keys for text cost model fix

On Sun, Feb 22, 2015 at 1:30 PM, Peter Geoghegan <pg(at)heroku(dot)com> wrote:
> You should try it with the data fully sorted like this, but with one
> tiny difference: The very last tuple is out of order. How does that
> look?

Another thing that may be of particular interest to you as a Czech
person is how various locales perform. I believe that the collation
rules of Czech and Hungarian are particularly complex, with several
passes often required for strcoll() (I think maybe more than 4). You
should either measure that, or control for it. I was prepared to
attribute the differences in the two systems to differences in compute
bandwidth between the CPUs involved (which are perhaps more noticeable
now, since memory latency is less of a bottleneck). However, the
inconsistent use of collations could actually matter here.

--
Peter Geoghegan