zero_damaged_pages having no effect - Mailing list pgsql-admin

From dan@kwasar.biz
Subject zero_damaged_pages having no effect
Date
Msg-id 1097523890.416ae2b2b571b@webmail.kwasar.biz
Whole thread Raw
List pgsql-admin
Hello again.

I have a database on 7.3.4, FreeBSD with corruption. dump & restore is definetly
not an option. Hardware is fine. Registed ECC memory on a SCSI hardware RAID5.
I got the corruption when the file system ran out of space.

I want to simply delete the damaged data and then I can reinsert it from it's
source.

Again, all I want is to delete the damaged data. A dump restore is not an
option.

So I set zero_damaged_pages to true in my postgres.conf.

sam=> select * from pg_settings where name ='zero_damaged_pages';
        name        | setting
--------------------+---------
 zero_damaged_pages | on
(1 row)

When I run a query that hits the damaged area, I was expecting a log message
saying that tuples were being zeroed, and a truncated result in my client.

But I got the usual:
sam=> SELECT * FROM channeldata where cd_id=6268 and tstamp<'2004-09-20' and
tstamp >'2004-09-15';
PANIC:  open of /psql/pg_clog/0C98 failed: No such file or directory
server closed the connection unexpectedly
        This probably means the server terminated abnormally
        before or while processing the request.
The connection to the server was lost. Attempting reset: Failed.
!>

Is there some extra trick here? I just want to delete the bad tuples. I can
restore the data from another source.

I really don't care if I need to take the database server down at 2am and use a
hex editor to clean this. I need my boss off my back. Please help me delete
these bad tuples.

Thanks again

Dan Hrabarchuk

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