Re: WAL consistency check facility

On Wed, Nov 2, 2016 at 1:11 PM, Kuntal Ghosh <kuntalghosh(dot)2007(at)gmail(dot)com> wrote:
> Rest of the suggestions are well-taken. I'll update the patch accordingly.
I've updated the last submitted patch(v10) with the following changes:
- added a block level flag BKPIMAGE_APPLY to distinguish backup image
blocks which needs to be restored during replay.
- at present, hash index operations are not WAL-logged. Hence, I've removed
the consistency check option for hash indices. It can be added later.

Few comments:
- Michael suggested to use an integer variable and bitwise-shift
operation to store
the RMGR values instead of using a boolean array. But, boolean array
implementation looks cleaner to me. For example,
+if (wal_consistency[rmid])
+ rechdr->xl_info |= XLR_CHECK_CONSISTENCY;

+include_image = needs_backup || wal_consistency[rmid];

- Another suggestion was to remove wal_consistency from PostgresNode.pm
because small buildfarm machines may suffer on it. Although I've no
experience in this matter, I would like to be certain that nothings breaks
in recovery tests after some modifications.

--
Thanks & Regards,
Kuntal Ghosh
EnterpriseDB: http://www.enterprisedb.com