On 6/20/15 12:55 PM, Tomas Vondra wrote:
Well, actually I think it would be even more appropriate for very large tables. With a 2.5TB table, you don't really care whether analyze collects 5GB or 8GB sample, the difference is rather minor compared to I/O generated by the other queries etc. The current sample is already random enough not to work well with read-ahead, and it scans only a slightly lower number of blocks.
Have we ever looked at generating new stats as part of a seqscan? I don't know how expensive the math is but if it's too much to push to a backend perhaps a bgworker could follow behind the seqscan.
-- Jim Nasby, Data Architect, Blue Treble Consulting, Austin TX Data in Trouble? Get it in Treble! http://BlueTreble.com -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
