Message-ID: <552D4EE3.3060708@BlueTreble.com>
Date: Tue, 14 Apr 2015 12:31:15 -0500
From: Jim Nasby <Jim.Nasby@BlueTreble.com>
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To: Etsuro Fujita <fujita.etsuro@lab.ntt.co.jp>, Tom Lane <tgl@sss.pgh.pa.us>
CC: Ashutosh Bapat <ashutosh.bapat@enterprisedb.com>, Kyotaro HORIGUCHI
 <horiguchi.kyotaro@lab.ntt.co.jp>, Heikki Linnakangas
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 <shigeru.hanada@gmail.com>, pgsql-hackers <pgsql-hackers@postgresql.org>
Subject: Re: inherit support for foreign tables
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On 4/14/15 5:49 AM, Etsuro Fujita wrote:
> postgres=# create foreign table ft1 (c1 int) server myserver options
> (table_name 't1');
> CREATE FOREIGN TABLE
> postgres=# create foreign table ft2 (c1 int) server myserver options
> (table_name 't2');
> CREATE FOREIGN TABLE
> postgres=# alter foreign table ft2 inherit ft1;
> ALTER FOREIGN TABLE
> postgres=# select * from ft1 for update;
> ERROR:  could not find junk tableoid1 column
> 
> I think this is a bug.  Attached is a patch fixing this issue.

What happens when the foreign side breaks the inheritance? Does the FDW
somehow know to check that fact for each query?

What do you gain from having the local table have inheritance?

Basically, I think we have to be very careful about implementing
features that imply the local side knows something about the persisted
state of the remote side (in this case, whether there's inheritance).
Anything like that sets us up for synchronization problems.
-- 
Jim Nasby, Data Architect, Blue Treble Consulting
Data in Trouble? Get it in Treble! http://BlueTreble.com


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