Following this bug reports from redhat https://bugzilla.redhat.com/show_bug.cgi?id=845233
it rising some dangerous issue:
If on any reasons you data file is zeroed after some power loss(it is the most known issue on XFS in the past) when you do
select count(*) from you_table you got zero if you table was in one 1GB(default) file or some other numbers !=count (*) from you_table before power loss
No errors, nothing suspicious in logs. No any checksum errors. Nothing.
Silent data loss is its pure form.
And thanks to all gods that you notice it before backup recycling which contains good data.
Keep in mind it while checking you "backups" in any forms (pg_dump or the more dangerous and short-spoken PITR file backup)
You data is always in danger with "zeroed data file is normal file" paradigm.
--
Alex Ignatov
Postgres Professional: http://www.postgrespro.com
The Russian Postgres Company
