On Thu, Jun 30, 2016 at 3:12 PM, Amit Kapila <amit.kapil...@gmail.com> wrote: > On Thu, Jun 30, 2016 at 9:13 AM, Andres Freund <and...@anarazel.de> wrote: >> On 2016-06-30 08:59:16 +0530, Amit Kapila wrote: >>> On Wed, Jun 29, 2016 at 10:30 PM, Andres Freund <and...@anarazel.de> wrote: >>> > On 2016-06-29 19:04:31 +0530, Amit Kapila wrote: >>> >> There is nothing in this record which recorded the information about >>> >> visibility clear flag. >>> > >>> > I think we can actually defer the clearing to the lock release? >>> >>> How about the case if after we release the lock on page, the heap page >>> gets flushed, but not vm and then server crashes? >> >> In the released branches there's no need to clear all visible at that >> point. Note how heap_lock_tuple doesn't clear it at all. So we should be >> fine there, and that's the part where reusing an existing record is >> important (for compatibility). >> > > For back branches, I agree that heap_lock_tuple is sufficient,
Even if we use heap_lock_tuple, If server crashed after flushed heap but not vm, after crash recovery the heap is still marked all-visible on vm. This case could be happen even on released branched, and could make IndexOnlyScan returns wrong result? Regards, -- Masahiko Sawada -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
