| From: | Robert Haas <robertmhaas(at)gmail(dot)com> |
|---|---|
| To: | Peter Geoghegan <pg(at)heroku(dot)com> |
| Cc: | Heikki Linnakangas <hlinnakangas(at)vmware(dot)com>, Pg Hackers <pgsql-hackers(at)postgresql(dot)org> |
| Subject: | Re: B-Tree support function number 3 (strxfrm() optimization) |
| Date: | 2014-09-16 20:45:10 |
| Message-ID: | CA+Tgmoa2FMWJ=2YNJ4mBhOk__VmAz5T_L1ZtFuiSNfsGA=sOFA@mail.gmail.com |
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| Lists: | pgsql-hackers |
On Mon, Sep 15, 2014 at 7:21 PM, Peter Geoghegan <pg(at)heroku(dot)com> wrote:
> On Mon, Sep 15, 2014 at 11:25 AM, Peter Geoghegan <pg(at)heroku(dot)com> wrote:
>> OK, I'll draft a patch for that today, including similar alterations
>> to varstr_cmp() for the benefit of Windows and so on.
>
> I attach a much simpler patch, that only adds an opportunistic
> "memcmp() == 0" before a possible strcoll(). Both
> bttextfastcmp_locale() and varstr_cmp() have the optimization added,
> since there is no point in leaving anyone out for this part.
Even though our testing seems to indicate that the memcmp() is
basically free, I think it would be good to make the effort to avoid
doing memcmp() and then strcoll() and then strncmp(). Seems like it
shouldn't be too hard.
--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company
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