-I encountered the problem of not being able to upgrade my instance (14->15) via pg_upgrade.
-The utility crashed with an error in out of memory.-
-After researching a bit I found that this happens at the moment of export schema with pg_dump.
-Then I tried to manually perform a dump schema with the parameter --binary-upgrade option and also got an out of memory.
-Digging a little deeper, I discovered quite a large number of blob objects in the database (pg_largeobject 10GB and pg_largeobject_metadata 1GB (31kk rows))
-I was able to reproduce the problem on a clean server by simply putting some random data in pg_largeobject_metadata
-$insert into pg_largeobject_metadata (select i,16390 from generate_series(107659,34274365) as i);
-and after 1-2 min get out of memory ( i tried on server with 4 and 8 gb RAM)
-Perhaps this is a bug? How can I perform an upgrade?
a quick and dirty solution might be an additional temporary swap space like this https://en.euro-linux.com/blog/creating-a-swap-file-or-how-to-deal-with-a-temporary-memory-shortage/