Fujii Masao <masao(dot)fujii(at)gmail(dot)com> writes:
> If so, it might be deleted after triggering the warm-standby. But, we cannot
> remove it because the latest xlog file which is required for normal recovery
> might exist in it. This is another undesirable scenario. Is this problem?
What recovery? In the problem case you're positing, the slave server
has executed a checkpoint and come up live. It's never going to be
interested in the old xlog again.
regards, tom lane