PostgreSQL ERROR: could not open file "base/.../..." - linux

Question

There are many queue_promotion_n tables where n is from 1 to 100.
There is an error on the 73 table with a fairly simple query
SELECT count(DISTINCT queue_id)
FROM "queue_promotion_73"
WHERE status_new > NOW() - interval '3 days';
ERROR: could not open file "base/16387/357386324.1" (target block
200005): No such file or directory
Uptime DB 23 days. How to fix it?

Answer 1

Check that you have up-to-date backups (or verify that your DB replica is in sync)
PostgreSQL wiki recommends stopping DB and rsync whole all PostgreSQL files to a safe location.
File where the table is physically stored seems to be missing. You can check where PostgreSQL stores data on disk using:
SELECT pg_relation_filepath('queue_promotion_73');
pg_relation_filepath
----------------------
base/16387/357386324
(1 row)
If you are sure that your hard drives/RAID controller works fine, you can try rebuilding the table. It is a good idea to try this on a replica or backup snapshot of the database first.
VACUUM FULL queue_promotion_73;
Check again the relation path:
SELECT pg_relation_filepath('queue_promotion_73');
it should be different and hopefully with all required files.
The cause could be related to a hardware issue, make sure to check DB consistency.