On 30.08.2013 05:55, Fujii Masao wrote:
* Result [tps] 1386.8 (compress_backup_block = off) 1627.7 (compress_backup_block = on)
It would be good to check how much of this effect comes from reducing the amount of data that needs to be CRC'd, because there has been some talk of replacing the current CRC-32 algorithm with something faster. See http://www.postgresql.org/message-id/20130829223004.gd4...@awork2.anarazel.de. It might even be beneficial to use one routine for full-page-writes, which are generally much larger than other WAL records, and another routine for smaller records. As long as they both produce the same CRC, of course.
Speeding up the CRC calculation obviously won't help with the WAL volume per se, ie. you still generate the same amount of WAL that needs to be shipped in replication. But then again, if all you want to do is to reduce the volume, you could just compress the whole WAL stream.
- Heikki -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
