Re: file cloning in pg_upgrade and CREATE DATABASE

On Mon, Mar 19, 2018 at 04:06:36PM +0900, Michael Paquier wrote:
> Any backend-side callers of copy_file() would not benefit from
> copyfile() on OSX. Shouldn't all that handling be inside copy_file(),
> similarly to what your patch actually does for pg_upgrade? I think that
> you should also consider fcopyfile() instead of copyfile() as it works
> directly on the file descriptors and share the same error handling as
> the others.

Two other things I have noticed as well:
1) src/bin/pg_rewind/copy_fetch.c could benefit from similar speed-ups I
think when copying data from source to target using the local mode of
pg_rewind. This could really improve cases where new relations are
added after a promotion.
2) XLogFileCopy() uses a copy logic as well. For large segments things
could be improved, however we need to be careful about filling in the
end of segments with zeros.
--
Michael