Re: [HACKERS] generated columns - Mailing list pgsql-hackers

From Pavel Stehule
Subject Re: [HACKERS] generated columns
Date
Msg-id CAFj8pRCnXSjxvDqDgruAbf36TEdZZHmV5=xAUbn8Pc2=wHX84A@mail.gmail.com
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In response to Re: [HACKERS] generated columns  (Peter Eisentraut <peter.eisentraut@2ndquadrant.com>)
Responses Re: [HACKERS] generated columns  (Peter Eisentraut <peter.eisentraut@2ndquadrant.com>)
List pgsql-hackers
Hi

pá 11. 1. 2019 v 9:31 odesílatel Peter Eisentraut <peter.eisentraut@2ndquadrant.com> napsal:
On 06/11/2018 13:27, Peter Eisentraut wrote:
> This is a small bug that I will fix in my next update.

Time for another update.  Lot's of rebasing, many things fixed,
including the ADD COLUMN bug you found, replication, foreign tables,
better caching, some corner cases in trigger behavior, more
documentation.  This addresses everything I've had in my notes, so it's
functionally and logically complete from my perspective.

I am looking on this patch - it is great feature.

The documentation contains paragraph

+      The generation expression can only use immutable functions and cannot
+      use subqueries or reference anything other than the current row in any
+      way.

It is necessary for stored columns?

I tested it with pseudo constant - current_timestamp, session_user. But current_database() is disallowed.

on second hand, this is strange

postgres=# create table foo3 (inserted text generated always as (current_timestamp) virtual);
CREATE TABLE

Regards

Pavel

--
Peter Eisentraut              http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services

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