Re: update ALTER TABLE with ATTACH PARTITION lock mode (docs)

On Mon, Oct 28, 2019 at 12:06:44PM -0300, Alvaro Herrera wrote:
> On 2019-Oct-28, Michael Paquier wrote:
> 
> > On Sun, Oct 27, 2019 at 07:12:07PM -0500, Justin Pryzby wrote:
> > > commit #898e5e32 (Allow ATTACH PARTITION with only ShareUpdateExclusiveLock)
> > > updates ddl.sgml but not alter_table.sgml, which only says:
> > > 
> > > https://www.postgresql.org/docs/12/release-12.html
> > > |An ACCESS EXCLUSIVE lock is held unless explicitly noted.
> > 
> > +     <para>
> > +      Attaching a partition acquires a <literal>SHARE UPDATE EXCLUSIVE</literal>
> > +      lock on the partitioned table, in addition to an
> > +      <literal>ACCESS EXCLUSIVE</literal> lock on the partition.
> > +     </para>
> > Updating the docs of ALTER TABLE sounds like a good idea.  This
> > sentence looks fine to me.  Perhaps others have suggestions?
> 
> Doesn't the command also acquire a lock on the default partition if
> there is one?  It sounds worth noting.

I suppose it should something other than partition(ed), since partitions can be
partitioned, too...

      Attaching a partition acquires a <literal>SHARE UPDATE EXCLUSIVE</literal>
      lock on the parent table, in addition to
      <literal>ACCESS EXCLUSIVE</literal> locks on the child table and the
      <literal>DEFAULT</literal> partition (if any).

Thanks,
Justin