Re: [HACKERS] freezing tuples ( was: Why is vacuum_freeze_min_age100m? )

2009-08-17 Thread Kevin Grittner
Jeff Davis pg...@j-davis.com wrote: There are two ways to do the threshold: 1. Constant fraction of vacuum_freeze_min_age 2. Extra GUC I appreciate that there may be room to improve this while protecting the forensic values; but there are already strategies for managing the day-to-day

[PERFORM] Re: [HACKERS] freezing tuples ( was: Why is vacuum_freeze_min_age100m? )

2009-08-13 Thread Kevin Grittner
Alvaro Herrera alvhe...@commandprompt.com wrote: Jeff Davis wrote: Why aren't we more opportunistic about freezing tuples? For instance, if we already have a dirty buffer in cache, we should be more aggressive about freezing those tuples than freezing tuples on disk. The most widely

Re: [PERFORM] Re: [HACKERS] freezing tuples ( was: Why is vacuum_freeze_min_age100m? )

2009-08-13 Thread Jeff Davis
On Thu, 2009-08-13 at 17:17 -0500, Kevin Grittner wrote: It wouldn't surprise me to find workloads where writing data three times (once for the data, once for hint bits, and once to freeze the tid) I'm not sure that we're limited to 3 times, here. I could be missing something, but if you have