On Wed, Feb 1, 2012 at 12:29 AM, Rosser Schwarz
<rosser(dot)schwarz(at)gmail(dot)com> wrote:
> Remember, DDL is transactional in PostgreSQL. In principle, you
> should be able to drop the index, do your inserts, and re-create the
> index without affecting concurrent users, if you do all of that inside
> an explicit transaction. Doing the inserts inside a transaction may
> speed them up, as well.
Creating an index requires an update lock on the table, and an
exclusive lock on the system catalog.
Even though with "CONCURRENTLY" it's only for a short while.
So it does affect concurrent users.