Not going into details how that happened, all started with a corrupt DB. It was OK on the file-system level, but trying to:

select count(*) from mytable 

resulted in the following:

ERROR: could not read block 257798 in file "pg_tblspc/16386/PG_9.6_201608131/16385/16506.1": read only 0 of 8192 bytes

The table is very large (~200GB) and contains some bytea columns with binary data. It is never updated, only inserted into and selected from. I run pg_dump on it, it was working for a long time, produced a ~200GB file, but failed in the end with a similar error:

pg_dump -Z9 -Fc -d mydatabase -t mytable -v -f /datadir/mytable.backup 

pg_dump: Dumping the contents of table "mytable" failed: PQgetResult() failed.

pg_dump: Error message from server: ERROR: could not read block 257798 in file "pg_tblspc/16386/PG_9.6_201608131/16385/16506.1": read only 0 of 8192 bytes

pg_dump: The command was: COPY public.mytable (id, account_id, fetched, col1, col2, col3, col4, col5) TO stdout;

Then I tried to restore it, again it was working a long time, in the end it took ~200GB space on that tablespace, however select count(*) from mytable returns 0.

 pg_restore -Fc -d mydatabase -v /datadir/mytable.backup pg_restore: processing data for table "public.mytable" 

and after a long time

pg_restore: could not read from input file: end of file

I would like to recover as many rows as possible, I suspect that all the data should be still there since it's basically immutable, and that just the last record is corrupted.

Is there a way to force Postgres to keep the records which were restored up till the failed one?