Re: Why this lock?

Johann Spies <johann.spies@gmail.com> writes:
> On 25 August 2015 at 15:52, Merlin Moncure <mmoncure@gmail.com> wrote:
>> creating and index requires exclusive access.  did you try the
>> concurrent variant?

> Yes. The one which I stopped after 5 days, was running concurrently.  There
> was a similar lock involved.

That lock type is used by CREATE INDEX CONCURRENTLY when it has to wait
out another transaction.  There is no way around this, it's an inherent
part of that algorithm.

http://www.postgresql.org/docs/9.4/static/sql-createindex.html#SQL-CREATEINDEX-CONCURRENTLY

            regards, tom lane