From: | John Naylor <john(dot)naylor(at)2ndquadrant(dot)com> |
---|---|
To: | Alexander Korotkov <a(dot)korotkov(at)postgrespro(dot)ru> |
Cc: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>, PostgreSQL Hackers <pgsql-hackers(at)lists(dot)postgresql(dot)org> |
Subject: | Re: jsonpath |
Date: | 2019-04-22 00:07:01 |
Message-ID: | CACPNZCsUJAdBK94Vn0C4AiCxdkTYRiaQ0AFdZdq8A8-WnGMrtg@mail.gmail.com |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-hackers |
On Sun, Apr 21, 2019 at 2:01 AM Alexander Korotkov
<a(dot)korotkov(at)postgrespro(dot)ru> wrote:
>
> On Thu, Apr 18, 2019 at 4:09 AM John Naylor <john(dot)naylor(at)2ndquadrant(dot)com> wrote:
> > I was wondering about that. I measured the current size of
> > yy_transition to be 36492 on my machine. With the flag -Cfe, which
> > gives the smallest representation without backtracking, yy_nxt is 6336
> > (there is no yy_transition). I'd say that's a large enough difference
> > that we'd want the smaller representation if it makes little
> > difference in performance.
>
> Did I understand correctly that you've tried the same version of
> jsonpath_scan.l with different flex flags?
Correct.
> Did you also notice if
> changes 1d88a75c made to jsonpath_scan.l have singnificant influence?
Trying the same measurements above with backtracking put back in,
jsonpath_yylex was actually larger by a few hundred bytes, and there
was almost no difference in the transition/nxt tables.
--
John Naylor https://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
From | Date | Subject | |
---|---|---|---|
Next Message | Tom Lane | 2019-04-22 00:27:20 | Re: jsonpath |
Previous Message | Alexander Korotkov | 2019-04-21 23:50:14 | Re: jsonpath |