From: Joe Conway <mail@joeconway.com>
To: Peter Eisentraut <peter.eisentraut@2ndquadrant.com>
To: Jaime Casanova <jaime.casanova@2ndquadrant.com>
Cc: pgsql-hackers <pgsql-hackers@postgresql.org>
Subject: Re: [HACKERS] Re: [HACKERS] generated columns
Date: Sat, 30 Dec 2017 13:04:52 -0800
Message-ID: <89e86cfd-6d13-fedc-89ed-268c84e7116f@joeconway.com> (raw)
In-Reply-To: <1bc948f8-3bab-6c54-50af-c0723a75b85f@2ndquadrant.com>
References: <b151f851-4019-bdb1-699e-ebab07d2f40a@2ndquadrant.com>
<CAJGNTeOxeQPFpEr35PME4yLayRzP_wwzt70kFrPztSTWHf-HDA@mail.gmail.com>
<CAJGNTeM+MCjA4dBhAdjJ-vR_CwY3u65cCcc+KvnahzLHZjxjbw@mail.gmail.com>
<1bc948f8-3bab-6c54-50af-c0723a75b85f@2ndquadrant.com>
On 12/27/2017 09:31 AM, Peter Eisentraut wrote:
> On 9/12/17 15:35, Jaime Casanova wrote:
>> On 10 September 2017 at 00:08, Jaime Casanova
>> <jaime.casanova@2ndquadrant.com> wrote:
>>>
>>> During my own tests, though, i found some problems:
>
> Here is an updated patch that should address the problems you have found.
In the commit message it says:
"The plan to is implement two kinds of generated columns:
virtual (computed on read) and stored (computed on write). This
patch only implements the virtual kind, leaving stubs to implement
the stored kind later."
and in the patch itself:
+<para>
+ The generation expression can refer to other columns in the table, but
+ not other generated columns. Any functions and operators used must be
+ immutable. References to other tables are not allowed.
+</para>
Question -- when the "stored" kind of generated column is implemented,
will the immutable restriction be relaxed? I would like, for example, be
able to have a stored generated column that executes now() whenever the
row is written/rewritten.
Joe
--
Crunchy Data - http://crunchydata.com
PostgreSQL Support for Secure Enterprises
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To: pgsql-hackers@postgresql.org
Cc: mail@joeconway.com, peter.eisentraut@2ndquadrant.com, jaime.casanova@2ndquadrant.com
Subject: Re: [HACKERS] Re: [HACKERS] generated columns
In-Reply-To: <89e86cfd-6d13-fedc-89ed-268c84e7116f@joeconway.com>
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