From: Konstantin Osipov <kostja.osipov@gmail.com> To: Aleksandr Lyapunov <alyapunov@tarantool.org> Cc: tarantool-patches@dev.tarantool.org Subject: Re: [Tarantool-patches] [PATCH] rfc: multi-directional iterators Date: Sat, 25 Apr 2020 12:03:20 +0300 [thread overview] Message-ID: <20200425090320.GB8860@atlas> (raw) In-Reply-To: <5e27bca5-14f4-6800-84c6-53f831cb83b6@tarantool.org> * Aleksandr Lyapunov <alyapunov@tarantool.org> [20/04/24 13:11]: > > +may want to select tuples with `a >= 1`, `b >= 1` but `c < 1`. Or, alternatively, > > +somebody may be willing to get tuples ordered by `a` and `b` in ascending order > > +but by `c` in descending order: `i:select({}, {iterator = {'GE', 'GE', 'LE'})`. > Those are not alternatives but independent options. One may wish to select: > `SELECT * FROM t WHERE a > 1 AND b < 1 ORDER BY a DESC, b ASC`. I agree. > My summary: > > 1. `select({1, 1}, {iterator='GE'})` is not equivalent to `SELECT .. > WHERE a>=1 AND b >= 1`. > 2. It is still possible to implement `iterator={'GE', 'GE'}` that will > suitable for that SQL SELECT. > 3. It is also possible to implement `order={'ASC', 'DESC'}` option in > select using the solution #1. I agree, but it's not urgent either. These queries are rare. -- Konstantin Osipov, Moscow, Russia
next prev parent reply other threads:[~2020-04-25 9:03 UTC|newest] Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-04-24 10:10 Aleksandr Lyapunov 2020-04-25 9:03 ` Konstantin Osipov [this message] -- strict thread matches above, loose matches on Subject: below -- 2020-01-26 20:54 Nikita Pettik 2020-01-27 19:34 ` Konstantin Osipov 2020-01-27 19:38 ` Konstantin Osipov 2020-04-25 9:00 ` Konstantin Osipov
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