PostgreSQL error:could not read block * in file "base/*/*": read only * of * bytes

base/16384/16845: base represents the tablespace, 16385 is the database, and 16845 is the file.

The default tablespace, known as pg_default. On disk, this will be the directory named base underneath the data_directory

nnm=# select oid, * from pg_tablespace
nnm-# ;
 oid  |  spcname   | spcowner | spcacl | spcoptions
------+------------+----------+--------+------------
 1663 | pg_default |       10 |        |
 1664 | pg_global  |       10 |        |
(2 rows)

nnm=# show data_directory;
              data_directory
-------------------------------------------
 /var/opt/OV/shared/nnm/databases/Postgres
(1 row)

# ll /var/opt/OV/shared/nnm/databases/Postgres/base
total 160
drwx------. 2 nmsdbmgr nmsdb  8192 Feb 26 02:04 1
drwx------. 2 nmsdbmgr nmsdb  8192 Feb  4 14:30 13286
drwx------. 2 nmsdbmgr nmsdb  8192 Feb  8 14:36 13287
drwx------. 2 nmsdbmgr nmsdb 69632 Feb 26 02:05 16384

This query below will provide the details of the relation for the given file.

nnm=# select n.nspname AS schema, c.relname AS realtion  from pg_class c inner join pg_namespace n on (c.relnamespace = n.oid) where c.relfilenode = ‘16845’  ;

To check the sanity of the table do a pg_dump of the table nms_disco_fdb  to which the index belongs, as pg_dump doesn’t use any indexes but reads the table data directly.

/opt/OV/nonOV/Postgres/bin/pg_dump -U postgres -d nnm -v  -t nms_disco_fdb > backup_pgbench_accounts.sql >> backup_nms_disco_fdb.log 2>&1

Now open the file backup_nms_disco_fdb.log  and check if there are entries. Which should indicate that the table data is fine and we have issues with index.