On Fri, Feb 24, 2017 at 10:09:50PM +0200, Ants Aasma wrote: > On Fri, Feb 24, 2017 at 9:37 PM, Bruce Momjian <br...@momjian.us> wrote: > > Oh, that's why we will hopefully eventually change the page checksum > > algorithm to use the special CRC32 instruction, and set a new checksum > > version --- got it. I assume there is currently no compile-time way to > > do this. > > Using CRC32 as implemented now for the WAL would be significantly > slower than what we have now due to instruction latency. Even the best > theoretical implementation using the CRC32 instruction would still be > about the same speed than what we have now. I haven't seen anybody > working on swapping out the current algorithm. And I don't really see > a reason to, it would introduce a load of headaches for no real gain.
Uh, I am confused. I thought you said we were leaving some performance on the table. What is that? I though CRC32 was SSE4.1. Why is CRC32 good for the WAL but bad for the page checksums? What about the WAL page images? -- Bruce Momjian <br...@momjian.us> http://momjian.us EnterpriseDB http://enterprisedb.com + As you are, so once was I. As I am, so you will be. + + Ancient Roman grave inscription + -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
