disable triggers isolated to transaction only?

I'm planning to split a large table into partitions. During the
migration, all new data will be added to the sub-tables, and I will be
moving the data from the master table to the proper sub tables at the
same time. The trick is that I have an INSERT trigger to keep track
of various counters. I need to be able to disable that trigger for
the data I'm moving, yet leave it intact for the new data being
inserted.

My question is this: will ALTER TABLE ONLY $subtable DISABLE TRIGGER
ALL within a transaction only affect my transaction, or will it affect
anyone inserting into this subtable. If it blocks external inserts
that's ok since my transactions are small while moving the data. I
guess at worse I lock the table.