On 21/01/17 17:31, Stephen Frost wrote: > Petr, > > * Petr Jelinek (petr.jeli...@2ndquadrant.com) wrote: >> On 21/01/17 16:40, Stephen Frost wrote: >>> * Petr Jelinek (petr.jeli...@2ndquadrant.com) wrote: >>>> On 21/01/17 11:39, Magnus Hagander wrote: >>>>> Is it time to enable checksums by default, and give initdb a switch to >>>>> turn it off instead? >>>> >>>> I'd like to see benchmark first, both in terms of CPU and in terms of >>>> produced WAL (=network traffic) given that it turns on logging of hint >>>> bits. >>> >>> Benchmarking was done previously, but I don't think it's really all that >>> relevant, we should be checksum'ing by default because we care about the >>> data and it's hard to get checksums enabled on a running system. >> >> I do think that performance implications are very relevant. And I >> haven't seen any serious benchmark that would incorporate all current >> differences between using and not using checksums. > > This is just changing the *default*, not requiring checksums to always > be enabled. We do not hold the same standards for our defaults as we do > for always-enabled code, for clear reasons- not every situation is the > same and that's why we have defaults that people can change.
I can buy that. If it's possible to turn checksums off without recreating data directory then I think it would be okay to have default on. >> The change of wal_level was supported by benchmark, I think it's >> reasonable to ask for this to be as well. > > No, it wasn't, it was that people felt the cases where changing > wal_level would seriously hurt performance didn't out-weigh the value of > making the change to the default. > Really? https://www.postgresql.org/message-id/d34ce5b5-131f-66ce-f7c5-eb406dbe0...@2ndquadrant.com https://www.postgresql.org/message-id/83b33502-1bf8-1ffb-7c73-5b61ddeb6...@2ndquadrant.com -- Petr Jelinek http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
