BUG #14384: pg_dump uses excessive amounts of memory for LOBs

From: boleslaw(dot)ziobrowski(at)yahoo(dot)pl
To: pgsql-bugs(at)postgresql(dot)org
Subject: BUG #14384: pg_dump uses excessive amounts of memory for LOBs
Date: 2016-10-20 07:56:49
Message-ID: 20161020075649.1397.16074@wrigleys.postgresql.org
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-bugs

The following bug has been logged on the website:

Bug reference: 14384
Logged by: Bolek Ziobrowski
Email address: boleslaw(dot)ziobrowski(at)yahoo(dot)pl
PostgreSQL version: 9.5.4
Operating system: Ubuntu 14.04.5 LTS
Description:

pg_dump seems to allocate memory proportional to the number of rows in
pg_largeobject (not necessarily correlated with size of these objects) ,
e.g. 4 GB for a few millions and about 26 GB for 30 millions of lobs .

Steps to reproduce :
psql :

create table large_object_test( a int, lobj oid );

insert into large_object_test select a.i,lo_from_bytea(0,
E'\\xffffff0000000000') from generate_series(1,5000000) as a(i) ;

cli:

pg_dump postgres > /tmp/dump.sql

top -o "%MEM"

Responses

Browse pgsql-bugs by date

  From Date Subject
Next Message strahinjak 2016-10-20 08:50:35 BUG #14385: Operator IS changed priority in 9.5
Previous Message Alf Normann Klausen 2016-10-19 20:02:36 Re: BUG #14370: pgagent_96 service typo?