From: | David Rowley <david(dot)rowley(at)2ndquadrant(dot)com> |
---|---|
To: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
Cc: | Robert Haas <robertmhaas(at)gmail(dot)com>, Peter Eisentraut <peter(dot)eisentraut(at)2ndquadrant(dot)com>, Amit Langote <Langote_Amit_f8(at)lab(dot)ntt(dot)co(dot)jp>, Stephen Frost <sfrost(at)snowman(dot)net>, Mark Dilger <hornschnorter(at)gmail(dot)com>, Dilip Kumar <dilipbalaut(at)gmail(dot)com>, Pg Hackers <pgsql-hackers(at)postgresql(dot)org> |
Subject: | Re: Boolean partitions syntax |
Date: | 2018-04-10 14:33:58 |
Message-ID: | CAKJS1f8QAF8bT7ixF21ScE8M3CN0c37xE5PT4XEvnthxete5Ng@mail.gmail.com |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-hackers |
On 3 February 2018 at 12:04, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> Perhaps more useful to discuss: would that truly be the semantics we want,
> or should we just evaluate the expression and have done? It's certainly
> arguable that "IN (random())" ought to draw an error, not compute some
> random value and use that. But if you are insistent on partition bounds
> being immutable in any strong sense, you've already got problems, because
> e.g. a timestamptz literal's interpretation isn't necessarily fixed.
> It's only after we've reduced the original input to Datum form that we
> can make any real promises about the value not moving. So I'm not seeing
> where is the bright line between "IN ('today')" and "IN (random())".
I see there's been some progress on this thread that's probably gone a
bit beyond here without the discussion about the desired semantics.
To kick that off, I'm wondering, in regards to the comment about
'today' vs random(); how does this differ from something like:
CREATE VIEW ... AS SELECT ... FROM ... WHERE datecol = 'today'; ?
In this case 'today' is going to be evaluated during the parse
analysis that's done during CREATE VIEW. Why would partitioning need
to be treated differently?
--
David Rowley http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Training & Services
From | Date | Subject | |
---|---|---|---|
Next Message | David Rowley | 2018-04-10 14:37:50 | Re: Boolean partitions syntax |
Previous Message | Dagfinn Ilmari =?utf-8?Q?Manns=C3=A5ker?= | 2018-04-10 14:31:28 | Re: Transform for pl/perl |