| From: | Merlin Moncure <mmoncure(at)gmail(dot)com> |
|---|---|
| To: | Andres Freund <andres(at)anarazel(dot)de> |
| Cc: | Robert Haas <robertmhaas(at)gmail(dot)com>, Heikki Linnakangas <heikki(dot)linnakangas(at)enterprisedb(dot)com>, Simon Riggs <simon(at)2ndquadrant(dot)com>, Kevin Grittner <Kevin(dot)Grittner(at)wicourts(dot)gov>, david(at)fetter(dot)org, aidan(at)highrise(dot)ca, stark(at)mit(dot)edu, pgsql-hackers(at)postgresql(dot)org |
| Subject: | Re: 16-bit page checksums for 9.2 |
| Date: | 2012-01-06 22:17:09 |
| Message-ID: | CAHyXU0y30PcpFx5Ar0AV-0C9kBb6uLa0-H7Tr_FaUMRNHTbqsw@mail.gmail.com |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-hackers |
On Fri, Jan 6, 2012 at 2:03 PM, Andres Freund <andres(at)anarazel(dot)de> wrote:
>> The standby can set hint bits locally that weren't set on the data it
>> received from the master. This will require rechecksumming and
>> rewriting the page, but obviously we can't write the WAL records
>> needed to protect those writes during recovery. So a crash could
>> create a torn page, invalidating the checksum.
> Err. Stupid me, thanks.
>
>> Ignoring checksum errors during Hot Standby operation doesn't fix it,
>> either, because eventually you might want to promote the standby, and
>> the checksum will still be invalid.
> Its funny. I have the feeling we all are missing a very obvious brilliant
> solution to this...
Like getting rid of hint bits?
merlin
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Robert Haas | 2012-01-06 22:24:32 | LWLOCK_STATS |
| Previous Message | Martijn van Oosterhout | 2012-01-06 22:07:18 | Re: Add SPI results constants available for PL/* |