Does running UPDATE Statistics on SQL 2008 r2 with full scan on a large table 50 million rows (non partitioned)? I am trying to confirm the following behavior.
a) takes any locks during the entire run? Not sure but I think no locks are taken however a sr. dba told me that it takes schema modify lock (hmm...)
b) cause blocking -- I don't think so
c) cause heavy IO -- as each and every page will be read into the memory and pollute the data page buffer cache. So generally you should do this off hours.