pgsql: Rename "pg_xlog" directory to "pg_wal".

Rename "pg_xlog" directory to "pg_wal".

"xlog" is not a particularly clear abbreviation for "write-ahead log",
and it sometimes confuses users into believe that the contents of the
"pg_xlog" directory are not critical data, leading to unpleasant
consequences.  So, rename the directory to "pg_wal".

This patch modifies pg_upgrade and pg_basebackup to understand both
the old and new directory layouts; the former is necessary given the
purpose of the tool, while the latter merely avoids an unnecessary
backward-compatibility break.

We may wish to consider renaming other programs, switches, and
functions which still use the old "xlog" naming to also refer to
"wal".  However, that's still under discussion, so let's do just this
much for now.

Discussion: CAB7nPqTeC-8+zux8_-4ZD46V7YPwooeFxgndfsq5Rg8ibLVm1A@mail.gmail.com

Michael Paquier

Branch
------
master

Details
-------
http://git.postgresql.org/pg/commitdiff/f82ec32ac30ae7e3ec7c84067192535b2ff8ec0e

Modified Files
--------------
doc/src/sgml/backup.sgml                     |  28 ++++----
doc/src/sgml/config.sgml                     |   6 +-
doc/src/sgml/func.sgml                       |   2 +-
doc/src/sgml/high-availability.sgml          |  14 ++--
doc/src/sgml/perform.sgml                    |   2 +-
doc/src/sgml/protocol.sgml                   |   6 +-
doc/src/sgml/ref/pg_resetxlog.sgml           |  10 +--
doc/src/sgml/ref/pg_rewind.sgml              |   4 +-
doc/src/sgml/ref/pg_xlogdump.sgml            |   2 +-
doc/src/sgml/ref/pgtestfsync.sgml            |   4 +-
doc/src/sgml/ref/pgupgrade.sgml              |   4 +-
doc/src/sgml/storage.sgml                    |   2 +-
doc/src/sgml/wal.sgml                        |  10 +--
src/backend/access/transam/timeline.c        |   4 +-
src/backend/access/transam/xlog.c            | 100 +++++++++++++--------------
src/backend/access/transam/xlogarchive.c     |   2 +-
src/backend/access/transam/xlogfuncs.c       |   2 +-
src/backend/replication/README               |   2 +-
src/backend/replication/basebackup.c         |  20 +++---
src/backend/replication/walreceiver.c        |   6 +-
src/backend/replication/walsender.c          |   4 +-
src/backend/storage/file/fd.c                |  16 ++---
src/bin/initdb/initdb.c                      |  12 ++--
src/bin/pg_basebackup/pg_basebackup.c        |  80 +++++++++++++--------
src/bin/pg_basebackup/t/010_pg_basebackup.pl |   8 +--
src/bin/pg_resetxlog/pg_resetxlog.c          |   2 +-
src/bin/pg_rewind/copy_fetch.c               |   4 +-
src/bin/pg_rewind/filemap.c                  |   8 +--
src/bin/pg_rewind/parsexlog.c                |   2 +-
src/bin/pg_rewind/t/004_pg_xlog_symlink.pl   |  10 +--
src/bin/pg_upgrade/exec.c                    |  79 +++++++++++++--------
src/bin/pg_xlogdump/pg_xlogdump.c            |   2 +-
src/common/file_utils.c                      |  39 +++++++----
src/include/access/xlog_internal.h           |   2 +-
src/include/catalog/catversion.h             |   2 +-
src/include/common/file_utils.h              |   3 +-
src/include/postmaster/pgarch.h              |   2 +-
37 files changed, 279 insertions(+), 226 deletions(-)