Re: pgsql: Adjust string comparison in jsonpath

On Mon, Aug 12, 2019 at 1:25 AM Thomas Munro <thomas.munro@gmail.com> wrote:
> On Mon, Aug 12, 2019 at 9:04 AM Andrew Dunstan
> <andrew.dunstan@2ndquadrant.com> wrote:
> > On 8/11/19 4:10 PM, Alexander Korotkov wrote:
> > > Adjust string comparison in jsonpath
> > >
> > > We have implemented jsonpath string comparison using default database locale.
> > > However, standard requires us to compare Unicode codepoints.  This commit
> > > implements that, but for performance reasons we still use per-byte comparison
> > > for "==" operator.  Thus, for consistency other comparison operators do per-byte
> > > comparison if Unicode codepoints appear to be equal.
> > >
> > > In some edge cases, when same Unicode codepoints have different binary
> > > representations in database encoding, we diverge standard to achieve better
> > > performance of "==" operator.  In future to implement strict standard
> > > conformance, we can do normalization of input JSON strings.
> > >
> >
> >
> > This appears to have upset prion when testing on en_US.iso885915.
>
> Also lapwing's "InstallCheck-fr_FR" stage crashed on this commit, when
> running JSON queries, on HEAD and REL_12_STABLE:
>
> https://buildfarm.postgresql.org/cgi-bin/show_log.pl?nm=lapwing&dt=2019-08-11%2021%3A02%3A32
> https://buildfarm.postgresql.org/cgi-bin/show_log.pl?nm=lapwing&dt=2019-08-11%2020%3A40%3A07

Thank you for pointing!  I hope I can investigate this shortly.

------
Alexander Korotkov
Postgres Professional: http://www.postgrespro.com
The Russian Postgres Company