Re: crash-safe visibility map, take three

On 30.11.2010 19:22, Tom Lane wrote:
> But having said that, I wonder whether we need a full-page image for
> a WAL-logged action that is known to involve only setting a single bit
> and updating LSN.  Would omitting the FPI be any more risky than what
> happens now (ie, the page does get written back to disk at some point,
> without any image from which it can be rewritten if the write fails...)

You have to write a full-page image if you update the LSN, because 
otherwise the next update that comes along will not write a full page image.

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