2013/3/18 Bruce Momjian <br...@momjian.us>: > On Sun, Mar 17, 2013 at 05:50:11PM -0700, Greg Smith wrote: >> As long as the feature is off by default, so that people have to >> turn it on to hit the biggest changed code paths, the exposure to >> potential bugs doesn't seem too bad. New WAL data is no fun, but >> it's not like this hasn't happened before. > > With a potential 10-20% overhead, I am unclear who would enable this at > initdb time.
everybody who has no 100% loaded server. I can see on almost all PostgreSQL instances load to 5 on 8CPU core instances. It is similar to PostgreSQL statistics - I remember so it did 20% slowdown too Regards Pavel > > I assume a user would wait until they suspected corruption to turn it > on, and because it is only initdb-enabled, they would have to > dump/reload their cluster. The open question is whether this is a > usable feature as written, or whether we should wait until 9.4. > > pg_upgrade can't handle this because the old/new clusters would have the > same catalog version number and the tablespace directory names would > conflict. Even if they are not using tablespaces, the old heap/index > files would not have checksums and therefore would throw an error as > soon as you accessed them. In fact, this feature is going to need > pg_upgrade changes to detect from pg_controldata that the old/new > clusters have the same checksum setting. > > -- > Bruce Momjian <br...@momjian.us> http://momjian.us > EnterpriseDB http://enterprisedb.com > > + It's impossible for everything to be true. + > > > -- > Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) > To make changes to your subscription: > http://www.postgresql.org/mailpref/pgsql-hackers -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
