Re: Copy

Tom Lane wrote:
>
> John Coers <coers@intrinsity.com> writes:
> > Does a COPY FROM block?  In case I am using the wrong terminology,
> > what I need to know is if I have multiple clients performing COPY FROM...PQputline()
> > using asynchronous connections, will I lose data?
>
> No.
>
> > Will the server simply execute them serially?
>
> They'll be executed in parallel, just the same as if each client had
> done a bunch of INSERTs wrapped in a BEGIN/END block.  You'd only see
> problems if clients inserted conflicting data (eg, identical keys in
> a column with a UNIQUE index).  You may care to read the documentation
> about multi-version concurrency control and locking.
>
>                         regards, tom lane

hmmmm...I get best performance with N=2 and force the clients to keep trying to
get a connection.  If I leave the default of N=32 the machine gets bogged down
to a complete standstill by 32 copies of 15k rows of data.  The CPU doesn't seem
stressed -- what may be causing the bottleneck?


--
John Coers            Intrinsity, Inc.
coers@intrinsity.com  Austin, Texas