> But even then, we don't actually have to track the *names* of the > files that have changed, just their RelFileNodes, since there's a > mapping function from the RelFileNode to the filename.
Right. I have noticed that too and have made changes to my implementaion. BTW, you need to track the block number as well. Files > 1GB may be splitted into separate files (segments). > > Of course, if there are lots of files, sync() may be faster than > > opening/fsync/closing all those files. > > This is true, and is something I hadn't actually thought of. So it > sounds like some testing would be in order. I regard the difference between sync() and fsync() does not affect too much to the whole performance. Checkpoint process is performed as a separate process and the fsync() part of checkpoint does nothing with WAL, that means other backend processes, busy with WAL IO will not be bothered. -- Tatsuo Ishii ---------------------------(end of broadcast)--------------------------- TIP 5: Have you checked our extensive FAQ? http://www.postgresql.org/docs/faqs/FAQ.html
