On 11/19/19 5:00 AM, Rushabh Lathia wrote: > > My colleague Suraj did testing and noticed the performance impact > with the checksums. On further testing, he found that specifically with > sha its more of performance impact.
We have found that SHA1 adds about 3% overhead when the backup is also compressed (gzip -6), which is what most people want to do. This percentage goes down even more if the backup is being transferred over a network or to an object store such as S3. We judged that the lower collision rate of SHA1 justified the additional expense. That said, making SHA256 optional seems reasonable. We decided not to make our SHA1 checksums optional to reduce the test matrix and because parallelism largely addressed performance concerns. Regards, -- -David da...@pgmasters.net
