On 01/21/2017 04:48 PM, Stephen Frost wrote:
> * Fujii Masao (masao.fujii@gmail.com) wrote:
>> If the performance overhead by the checksums is really negligible,
>> we may be able to get rid of wal_log_hints parameter, as well.
>
> Prior benchmarks showed it to be on the order of a few percent, as I
> recall, so I'm not sure that we can say it's negligible (and that's not
> why Magnus was proposing changing the default).
It might be worth looking into using the CRC CPU instruction to reduce
this overhead, like we do for the WAL checksums. Since that is a
different algorithm it would be a compatibility break and we would need
to support the old algorithm for upgraded clusters..
Andreas
