Re: Block-level CRC checks

Jonah H. Harris wrote:
> On Thu, Oct 2, 2008 at 10:09 AM, Andrew Chernow <ac@esilo.com> wrote:
>> Would it not be better to add a boolean bit or byte to inidcate the crc
>> state?
> 
> Ideally, though we don't have any spare bits to play with in MAXALIGN=4.

In the page header? There's plenty of free bits in pd_flags.

But isn't it a bit dangerous to have a single flag on the page 
indicating whether the CRC is valid or not? Any corruption that flips 
that bit would make the CRC check to be skipped.

--   Heikki Linnakangas  EnterpriseDB   http://www.enterprisedb.com