Re: Proposal: Incremental Backup

On 07/25/2014 11:49 AM, Claudio Freire wrote:
>> I agree with much of that.  However, I'd question whether we can
>> > really seriously expect to rely on file modification times for
>> > critical data-integrity operations.  I wouldn't like it if somebody
>> > ran ntpdate to fix the time while the base backup was running, and it
>> > set the time backward, and the next differential backup consequently
>> > omitted some blocks that had been modified during the base backup.
> I was thinking the same. But that timestamp could be saved on the file
> itself, or some other catalog, like a "trusted metadata" implemented
> by pg itself, and it could be an LSN range instead of a timestamp
> really.

What about requiring checksums to be on instead, and checking the
file-level checksums?   Hmmm, wait, do we have file-level checksums?  Or
just page-level?

-- 
Josh Berkus
PostgreSQL Experts Inc.
http://pgexperts.com