Kevin Brown <kevin@sysexperts.com> writes:
> Tom Lane wrote:
>> Basically, one should only turn this variable on after giving up on the
>> possibility of getting any data out of the broken page itself. It would
>> be folly to run with it turned on as a normal setting.
> This statement should *definitely* go into the documentation for the
> option, then...
Here's what I put in --- feel free to suggest better wording.
ZERO_DAMAGED_PAGES (boolean)
Detection of a damaged page header normally causes PostgreSQL to report an error, aborting the current
transaction.Setting zero_damaged_pages to true causes the system to instead report a warning, zero out the
damagedpage, and continue processing. This behavior <emphasis>will lose data</>, namely all the rows on the
damagedpage. But it allows you to get past the error and retrieve rows from any undamaged pages that may be present
inthe table. So it is useful for recovering data if corruption has occurred due to hardware or software error.
Thedefault setting is off, and it can only be changed by a superuser.
regards, tom lane