On Mon, Apr 06, 2015 at 12:07:47PM -0500, Jim Nasby wrote: > ... > As I understand it, the goal here is to prevent huge amounts of > periodic freeze work due to XID wraparound. I don't think we need > the Freeze state to accomplish that. > > With a single bit per page in the Frozen Map, checking a 800GB table > would require reading a mere 100MB of FM. That's pretty tiny, and > largely accomplishes the goal. > > Obviously it would be nice to eliminate even that 100MB read, but I > suggest you leave that for a 3rd patch. I think you'll find that > just getting the first 2 accomplished will be a significant amount > of work. >
Hi, I may have my math wrong, but 800GB ~ 100M pages or 12.5MB and not 100MB. Regards, Ken -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
