Hello Takahashi-san, I am reluctant to draw conclusions about the general performance of this patch from one example. It seems that the performance could depend on many things: table size, column definitions, row width, hardware, OS version, shared_buffers, max_wal_size. I don't think we can say from your test here that performance is always worse on Windows. If it is, then I agree that we should think of what to do about it; but it seems possible to me that the behavior will be different in other circumstances.
What I don't understand is why increasing the number of blocks should be worse. The comment before the FileZero() call has a comment explaining why a larger extension is thought to be better. If it's wrong, we should try to figure out why it's wrong. But it seems quite surprising that doing more work at once would be less efficient. That's not usually how things work. -- Robert Haas EDB: http://www.enterprisedb.com
