On 9 April 2013 08:36, Jeff Davis <pg...@j-davis.com> wrote: > 1. I believe that the issue I brought up at the end of this email: > > http://www.postgresql.org/message-id/1365035537.7580.380.camel@sussancws0025 > > is a real issue. In lazy_vacuum_page(), the following sequence can > happen when checksums are on: > > a. PageSetAllVisible > b. Pass heap page to visibilitymap_set > c. visibilitymap_set logs the heap page and sets the LSN > d. MarkBufferDirty > > If a checkpoint happens between (c) and (d), then we have a problem. The > fix is easy: just mark the heap buffer dirty first. There's another call > site that looks like a potential problem, but I don't think it is. I > simplified the code there to make it (hopefully) more clearly correct.
Applied > 2. A cleanup patch to pass the buffer_std flag down through > MarkBufferDirtyHint. This is a matter of preference and purely cosmetic, > so it might not be wanted. The reason I thought it was useful is that a > future caller that sets a hint on a non-standard buffer might easily > miss the assumption that we have a standard buffer. Skipped that for now. Do we really need it? Can you set a hint on a non-standard buffer? -- Simon Riggs http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
