Hi, On Fri, Jun 13, 2014 at 7:24 PM, Heikki Linnakangas <hlinnakan...@vmware.com> wrote: > Yeah, that seems like a better design, after all. > > Attached is a new patch. It now keeps the current pg_clog unchanged, but > adds a new pg_csnlog besides it. pg_csnlog is more similar to pg_subtrans > than pg_clog: it's not WAL-logged, is reset at startup, and segments older > than GlobalXmin can be truncated. > > This addresses the disk space consumption, and simplifies pg_upgrade. > > There are no other significant changes in this new version, so it's still > very much WIP. But please take a look! >
Thanks for working on this important patch. I know this patch is still largely a WIP but I would like to report an observation. I applied this patch and did a few pgbench runs with 32 clients (this is on a not so powerful VM, by the way) . Perhaps you suspect such a thing already but I observed a relatively larger percentage of time being spent in XLogInsert(). Perhaps XLogCtlInsert.insertpos_lck contention via GetXLogInsertRecPtr()? -- Amit -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers