On Mon, May 6, 2019 at 12:05 PM Tom Lane <t...@sss.pgh.pa.us> wrote: > Robert Haas <robertmh...@gmail.com> writes: > > ... I guess you could incur the overhead repeatedly if the relation starts > > out at 1 block, grows to 4, is vacuumed back down to 1, lather, rinse, > > repeat, but is that actually realistic? > > While I've not studied the patch, I assumed that once a relation has an > FSM it won't disappear. Making it go away again if the relation gets > shorter seems both fairly useless and a promising source of bugs.
Right, I think so too. That's not what I as going for, though. I was trying to discuss a scenario where the relation repeatedly grows, never reaching the size at which the FSM would be created, and then is repeatedly truncated again. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company
