On Thu, Feb 16, 2017 at 9:58 PM, David Christensen <da...@endpoint.com> wrote:
> Extracted from a larger patch, this patch provides the basic > infrastructure for turning data > checksums off in a cluster. This also sets up the necessary pg_control > fields to support the > necessary multiple states for handling the transitions. > > We do a few things: > > - Change "data_checksums" from a simple boolean to "data_checksum_state", > an enum type for all of > the potentially-required states for this feature (as well as enabling). > > - Add pg_control support for parsing/displaying the new setting. > > - Distinguish between the possible checksum states and be specific about > whether we care about > checksum read failures or write failures at all call sites, turning > DataChecksumsEnabled() into two > functions: DataChecksumsEnabledReads() and DataChecksumsEnabledWrites(). > > - Create a superuser function pg_disable_checksums() to perform the actual > disabling of this in the > cluster. > > I have *not* changed the default in initdb to enable checksums, but this > would be trivial. > Per the point made by somebody else (I think Simon?) on the other thread, I think it also needs WAL support. Otherwise you turn it off on the master, but it remains on on a replica which will cause failures once datablocks without checksum starts replicating. -- Magnus Hagander Me: http://www.hagander.net/ Work: http://www.redpill-linpro.com/
