Thanks for the response.
Sure, I thought about it and even bought another drive. The current drive is SSD, as far as I'm concerned write operations degrade SSDs.
 
Even so, why other queries work fine? Why the query joining two tables instead of three works fine?
 
Cheers,
Serg
 
30.08.2023, 00:07, "Rick Otten" <rottenwindfish@gmail.com>:
 
 
On Tue, Aug 29, 2023 at 3:57 PM Rondat Flyag <rondatflyag@yandex.ru> wrote:
I took the dump just to store it on another storage (external HDD). I didn't do anything with it.
 
29.08.2023, 21:42, "Jeff Janes" <jeff.janes@gmail.com>:
 
 
On Tue, Aug 29, 2023 at 1:47 PM Rondat Flyag <rondatflyag@yandex.ru> wrote:
I have a legacy system that uses `Posgresql 9.6` and `Ubuntu 16.04`. Everything was fine several days ago even with standard Postgresql settings. I dumped a database with the compression option (maximum compression level -Z 9) in order to have a smaller size (`pg_dump --compress=9 database_name > database_name.sql`). After that I got a lot of problems.
 
You describe taking a dump of the database, but don't describe doing anything with it.  Did you replace your system with one restored from that dump?  If so, did vacuum and analyze afterwards?
 
Cheers,
 
Jeff
 
Since this is a very old system and backups are fairly I/O intensive, it is possible you have a disk going bad?  Sometimes after doing a bunch of I/O on an old disk, it will accelerate its decline.  You could be about to lose it altogether.