Re: Why copy_relation_data only use wal whenWALarchivingis enabled

> Heikki Linnakangas  writes:
> I tend to agree that truncating the file, and extending the fsync
> request mechanism to actually delete it after the next checkpoint,
> is the most reasonable route to a fix.
>

How about just allowing to use wal even WAL archiving is disabled?
It seems that recovery of "XLOG_HEAP_NEWPAGE" record will do the
right thing for us, look at "heap_xlog_newpage": XLogReadBuffer
with init=true will extend the block rightly and rebuild it rightly.

Someone may say that it's not worth recording xlog for operations
such as copy_relation_data, but these operations shouldn't happen
frequently.