From: Julien Rouhaud [mailto:rjuju...@gmail.com] > FWIW, I prefer shrink over truncate, though I'd rather go with > vacuum_shink_enabled as suggested previously.
Thanks. I'd like to leave a committer to choose the name. FWIW, I chose shrink_enabled rather than vacuum_shrink_enabled because this property may be used in other shrink situations in the future. What I imagined was that with the zheap, DELETE or some maintenance operation, not vacuum, may try to shrink the table. I meant this property to indicate "whether this table shrinks or not" regardless of the specific operation that can shrink the table. > I'm not sure that I get this comment. Since both require a > ShareUpdateExclusiveLock, you can't change the parameter while a > VACUUM is active on that table. Did you wanted to use another lock > mode? No, changing the parameter acquires ShareUpdaeExclusive lock. I just imitated the description for n_distinct in the same comment block. The meaning is that the setting cannot be changed during VACUUM, so in-flight VACUUM is not affected. Regards Takayuki Tsunakawa
