Re: WAL consistency check facility

On Thu, Aug 25, 2016 at 9:41 AM, Kuntal Ghosh
<kuntalghosh.2007@gmail.com> wrote:
> 2. For Btree pages, I've masked BTP_HALF_DEAD, BTP_SPLIT_END,
> BTP_HAS_GARBAGE and BTP_INCOMPLETE_SPLIT flags.

Why? I think that you should only perform this kind of masking where
it's clearly strictly necessary.

It is true that nbtree can allow cases where LP_DEAD is set with only
a share lock (by read-only queries), so I can see why BTP_HAS_GARBAGE
might need to be excluded; this is comparable to the heapam's use of
hint bits. However, it is unclear why you need to mask the remaining
btpo_flags that you list, because the other flags have clear-cut roles
in various atomic operations that we WAL-log.

-- 
Peter Geoghegan