Noted by Noah Misch, patch by Fujii Masao
WAL segments that cannot be found in the archive will be sought in
pg_xlog/>; this allows use of recent un-archived segments.
However, segments that are available from the archive will be used in
- preference to files in pg_xlog/>. The system will not
- overwrite the existing contents of pg_xlog/> when retrieving
- archived files.
+ preference to files in pg_xlog/>.