Re: COPY and heap_sync

On Sat, Aug 30, 2014 at 11:56 AM, Jeff Janes <jeff.janes@gmail.com> wrote:
>
> If you insert tuples with COPY into a table created or truncated in the same transaction, at the end of the COPY it calls heap_sync.
>
> But there cases were people use COPY in a loop with a small amount of data in each statement.  Now it is calling heap_sync many times, and if NBuffers is large doing that gets very slow.
>
> Could the heap_sync be safely delayed until the end of the transaction, rather than the end of the COPY?

Wouldn't unconditionally delaying sync until end of transaction

can lead to burst of I/O at that time especially if there are many

such copy commands in a transaction, leading to delay in some

other operation's that might be happening concurrently in the

system.