On Mon, Oct 18, 2021, at 8:53 PM, Alvaro Herrera wrote: > On 2021-Oct-18, David G. Johnston wrote: > > > On Mon, Oct 18, 2021 at 4:02 PM Alvaro Herrera <alvhe...@alvh.no-ip.org> > > wrote: > > > > Given that the first stage uses statistic target=1, running this option > > > in a database with any stats at all is probably a bad idea. > > > > Add the word "only"? > > > > This option is only useful to analyze a database... > > Maybe this is sufficient, since it would drive people away from trying > to do anything else than help upgrades with it. +1. I like your 2nd suggestion.
"This option is only useful to analyze a database that was newly populated from a restored dump or by <command>pg_upgrade</command>. Beware that running with this option in a database with existing statistics may cause query optimizer choices to become transiently worse, because of the very low statistics target that is used in the early stages." > > > "Run several (currently three) stages of analyze with different > > configuration settings, to produce usable statistics faster. The first of > > these stages will remove any existing statistics even if they use a larger > > statistic target configuration." > > .. yeah, this is another option. We might include it too but I would suggest "replace" instead of "remove" because it seems there won't be statistics after the first stage. -- Euler Taveira EDB https://www.enterprisedb.com/
