Subject: Re: pg_upgrade failing for 200+ million Large Objects
To: Andrew Dunstan <andrew@dunslane.net>, Tom Lane <tgl@sss.pgh.pa.us>
Cc: Magnus Hagander <magnus@hagander.net>,
 Robins Tharakan <tharakan@gmail.com>,
 Peter Eisentraut <peter.eisentraut@enterprisedb.com>,
 "pgsql-hackers@postgresql.org" <pgsql-hackers@postgresql.org>
References: <a9f9376f1c3343a6bb319dce294e20ac@EX13D05UWC001.ant.amazon.com>
 <CABUevEwyLb9VE0D+bAQtUnaA7bffXYzBpopYuh7kGTQxY9T5_g@mail.gmail.com>
 <CAEP4nAw2WA1wyb9LG7BOEuN3Xr-xWiZZ0w_hKtpyvdUPKmcAJA@mail.gmail.com>
 <1742698.1615221182@sss.pgh.pa.us>
 <CABUevEzvU07CqwGdaOmxNfDtrkY-xEcLjiN3GAmurowyCnbG7w@mail.gmail.com>
 <1743618.1615222719@sss.pgh.pa.us>
 <4fbf92f2-ec91-f4fa-a259-f0968e34f3d7@wi3ck.info>
 <181907.1616253799@sss.pgh.pa.us>
 <147fa478-510b-18ef-5323-9c1725b2493c@wi3ck.info>
 <c2a43a97-e551-ea6d-7a4f-a4709b4e0cbd@dunslane.net>
From: Jan Wieck <jan@wi3ck.info>
Message-ID: <5bdcb010-ecdd-c69a-b441-68002fc38483@wi3ck.info>
Date: Sun, 21 Mar 2021 12:56:02 -0400
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101
 Thunderbird/78.8.0
MIME-Version: 1.0
In-Reply-To: <c2a43a97-e551-ea6d-7a4f-a4709b4e0cbd@dunslane.net>
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Language: en-US
Content-Transfer-Encoding: 7bit
Archived-At: 
 <https://www.postgresql.org/message-id/5bdcb010-ecdd-c69a-b441-68002fc38483%40wi3ck.info>
Precedence: bulk

On 3/21/21 7:47 AM, Andrew Dunstan wrote:
> One possible (probable?) source is the JDBC driver, which currently
> treats all Blobs (and Clobs, for that matter) as LOs. I'm working on
> improving that some: <https://github.com/pgjdbc/pgjdbc/pull/2093>

You mean the user is using OID columns pointing to large objects and the 
JDBC driver is mapping those for streaming operations?

Yeah, that would explain a lot.


Thanks, Jan

-- 
Jan Wieck
Principle Database Engineer
Amazon Web Services