Replace "transaction log" with "write-ahead log"

This makes documentation and error messages match the renaming of "xlog"
to "wal" in APIs and file naming.

20 files changed, 75 insertions, 78 deletions

diff --git a/src/backend/access/transam/timeline.c b/src/backend/access/transam/timeline.c
index a11f0f85264..b442e7aa88f 100644
--- a/src/backend/access/transam/timeline.c
+++ b/src/backend/access/transam/timeline.c
@@ -151,7 +151,7 @@ readTimeLineHistory(TimeLineID targetTLI)
 		if (nfields != 3)
 			ereport(FATAL,
 					(errmsg("syntax error in history file: %s", fline),
-			   errhint("Expected a transaction log switchpoint location.")));
+			   errhint("Expected a write-ahead log switchpoint location.")));
 
 		if (result && tli <= lasttli)
 			ereport(FATAL,
diff --git a/src/backend/access/transam/transam.c b/src/backend/access/transam/transam.c
index 562b53be9aa..968b2323647 100644
--- a/src/backend/access/transam/transam.c
+++ b/src/backend/access/transam/transam.c
@@ -1,7 +1,7 @@
 /*-------------------------------------------------------------------------
  *
  * transam.c
- *	  postgres transaction log interface routines
+ *	  postgres transaction (commit) log interface routines
  *
  * Portions Copyright (c) 1996-2017, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index 5d6f8b75b8c..bc5fb4bb83d 100644
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -1,7 +1,7 @@
 /*-------------------------------------------------------------------------
  *
  * xlog.c
- *		PostgreSQL transaction log manager
+ *		PostgreSQL write-ahead log manager
  *
  *
  * Portions Copyright (c) 1996-2017, PostgreSQL Global Development Group
@@ -3532,7 +3532,7 @@ XLogFileOpen(XLogSegNo segno)
 	if (fd < 0)
 		ereport(PANIC,
 				(errcode_for_file_access(),
-			errmsg("could not open transaction log file \"%s\": %m", path)));
+			errmsg("could not open write-ahead log file \"%s\": %m", path)));
 
 	return fd;
 }
@@ -3838,7 +3838,7 @@ RemoveOldXlogFiles(XLogSegNo segno, XLogRecPtr PriorRedoPtr, XLogRecPtr endptr)
 	if (xldir == NULL)
 		ereport(ERROR,
 				(errcode_for_file_access(),
-				 errmsg("could not open transaction log directory \"%s\": %m",
+				 errmsg("could not open write-ahead log directory \"%s\": %m",
 						XLOGDIR)));
 
 	/*
@@ -3913,7 +3913,7 @@ RemoveNonParentXlogFiles(XLogRecPtr switchpoint, TimeLineID newTLI)
 	if (xldir == NULL)
 		ereport(ERROR,
 				(errcode_for_file_access(),
-				 errmsg("could not open transaction log directory \"%s\": %m",
+				 errmsg("could not open write-ahead log directory \"%s\": %m",
 						XLOGDIR)));
 
 	/*
@@ -3994,7 +3994,7 @@ RemoveXlogFile(const char *segname, XLogRecPtr PriorRedoPtr, XLogRecPtr endptr)
 							   true, recycleSegNo, true))
 	{
 		ereport(DEBUG2,
-				(errmsg("recycled transaction log file \"%s\"",
+				(errmsg("recycled write-ahead log file \"%s\"",
 						segname)));
 		CheckpointStats.ckpt_segs_recycled++;
 		/* Needn't recheck that slot on future iterations */
@@ -4006,7 +4006,7 @@ RemoveXlogFile(const char *segname, XLogRecPtr PriorRedoPtr, XLogRecPtr endptr)
 		int			rc;
 
 		ereport(DEBUG2,
-				(errmsg("removing transaction log file \"%s\"",
+				(errmsg("removing write-ahead log file \"%s\"",
 						segname)));
 
 #ifdef WIN32
@@ -4026,7 +4026,7 @@ RemoveXlogFile(const char *segname, XLogRecPtr PriorRedoPtr, XLogRecPtr endptr)
 		{
 			ereport(LOG,
 					(errcode_for_file_access(),
-			   errmsg("could not rename old transaction log file \"%s\": %m",
+			   errmsg("could not rename old write-ahead log file \"%s\": %m",
 					  path)));
 			return;
 		}
@@ -4108,7 +4108,7 @@ CleanupBackupHistory(void)
 	if (xldir == NULL)
 		ereport(ERROR,
 				(errcode_for_file_access(),
-				 errmsg("could not open transaction log directory \"%s\": %m",
+				 errmsg("could not open write-ahead log directory \"%s\": %m",
 						XLOGDIR)));
 
 	while ((xlde = ReadDir(xldir, XLOGDIR)) != NULL)
@@ -4117,9 +4117,8 @@ CleanupBackupHistory(void)
 		{
 			if (XLogArchiveCheckDone(xlde->d_name))
 			{
-				ereport(DEBUG2,
-				(errmsg("removing transaction log backup history file \"%s\"",
-						xlde->d_name)));
+				elog(DEBUG2, "removing WAL backup history file \"%s\"",
+					 xlde->d_name);
 				snprintf(path, sizeof(path), XLOGDIR "/%s", xlde->d_name);
 				unlink(path);
 				XLogArchiveCleanup(xlde->d_name);
@@ -5074,7 +5073,7 @@ BootStrapXLOG(void)
 			errno = ENOSPC;
 		ereport(PANIC,
 				(errcode_for_file_access(),
-			  errmsg("could not write bootstrap transaction log file: %m")));
+			  errmsg("could not write bootstrap write-ahead log file: %m")));
 	}
 	pgstat_report_wait_end();
 
@@ -5082,13 +5081,13 @@ BootStrapXLOG(void)
 	if (pg_fsync(openLogFile) != 0)
 		ereport(PANIC,
 				(errcode_for_file_access(),
-			  errmsg("could not fsync bootstrap transaction log file: %m")));
+			  errmsg("could not fsync bootstrap write-ahead log file: %m")));
 	pgstat_report_wait_end();
 
 	if (close(openLogFile))
 		ereport(PANIC,
 				(errcode_for_file_access(),
-			  errmsg("could not close bootstrap transaction log file: %m")));
+			  errmsg("could not close bootstrap write-ahead log file: %m")));
 
 	openLogFile = -1;
 
@@ -8432,7 +8431,7 @@ LogCheckpointEnd(bool restartpoint)
 	average_usecs = average_sync_time - (uint64) average_secs *1000000;
 
 	elog(LOG, "%s complete: wrote %d buffers (%.1f%%); "
-		 "%d transaction log file(s) added, %d removed, %d recycled; "
+		 "%d WAL file(s) added, %d removed, %d recycled; "
 		 "write=%ld.%03d s, sync=%ld.%03d s, total=%ld.%03d s; "
 		 "sync files=%d, longest=%ld.%03d s, average=%ld.%03d s; "
 		 "distance=%d kB, estimate=%d kB",
@@ -8842,7 +8841,7 @@ CreateCheckPoint(int flags)
 	 */
 	if (shutdown && checkPoint.redo != ProcLastRecPtr)
 		ereport(PANIC,
-				(errmsg("concurrent transaction log activity while database system is shutting down")));
+				(errmsg("concurrent write-ahead log activity while database system is shutting down")));
 
 	/*
 	 * Remember the prior checkpoint's redo pointer, used later to determine
diff --git a/src/backend/access/transam/xlogfuncs.c b/src/backend/access/transam/xlogfuncs.c
index aa47b0dcffc..8568c8abd64 100644
--- a/src/backend/access/transam/xlogfuncs.c
+++ b/src/backend/access/transam/xlogfuncs.c
@@ -2,7 +2,7 @@
  *
  * xlogfuncs.c
  *
- * PostgreSQL transaction log manager user interface functions
+ * PostgreSQL write-ahead log manager user interface functions
  *
  * This file contains WAL control and information functions.
  *
diff --git a/src/backend/access/transam/xlogutils.c b/src/backend/access/transam/xlogutils.c
index fb7f2e79746..d7f2e55b090 100644
--- a/src/backend/access/transam/xlogutils.c
+++ b/src/backend/access/transam/xlogutils.c
@@ -2,7 +2,7 @@
  *
  * xlogutils.c
  *
- * PostgreSQL transaction log manager utility routines
+ * PostgreSQL write-ahead log manager utility routines
  *
  * This file contains support routines that are used by XLOG replay functions.
  * None of this code is used during normal system operation.
diff --git a/src/backend/postmaster/checkpointer.c b/src/backend/postmaster/checkpointer.c
index d12db0d5a7b..a8dc355eada 100644
--- a/src/backend/postmaster/checkpointer.c
+++ b/src/backend/postmaster/checkpointer.c
@@ -626,9 +626,8 @@ CheckArchiveTimeout(void)
 			 * assume nothing happened.
 			 */
 			if ((switchpoint % XLogSegSize) != 0)
-				ereport(DEBUG1,
-						(errmsg("transaction log switch forced (archive_timeout=%d)",
-								XLogArchiveTimeout)));
+				elog(DEBUG1, "write-ahead log switch forced (archive_timeout=%d)",
+					 XLogArchiveTimeout);
 		}
 
 		/*
diff --git a/src/backend/postmaster/pgarch.c b/src/backend/postmaster/pgarch.c
index f3f58bd3908..2dce39fdefd 100644
--- a/src/backend/postmaster/pgarch.c
+++ b/src/backend/postmaster/pgarch.c
@@ -482,7 +482,7 @@ pgarch_ArchiverCopyLoop(void)
 				if (++failures >= NUM_ARCHIVE_RETRIES)
 				{
 					ereport(WARNING,
-							(errmsg("archiving transaction log file \"%s\" failed too many times, will try again later",
+							(errmsg("archiving write-ahead log file \"%s\" failed too many times, will try again later",
 									xlog)));
 					return;		/* give up archiving for now */
 				}
@@ -628,8 +628,7 @@ pgarch_archiveXlog(char *xlog)
 
 		return false;
 	}
-	ereport(DEBUG1,
-			(errmsg("archived transaction log file \"%s\"", xlog)));
+	elog(DEBUG1, "archived write-ahead log file \"%s\"", xlog);
 
 	snprintf(activitymsg, sizeof(activitymsg), "last was %s", xlog);
 	set_ps_display(activitymsg, false);
diff --git a/src/backend/postmaster/postmaster.c b/src/backend/postmaster/postmaster.c
index 01f1c2805f0..fdce5524f4c 100644
--- a/src/backend/postmaster/postmaster.c
+++ b/src/backend/postmaster/postmaster.c
@@ -5036,7 +5036,7 @@ sigusr1_handler(SIGNAL_ARGS)
 	{
 		/*
 		 * Send SIGUSR1 to archiver process, to wake it up and begin archiving
-		 * next transaction log file.
+		 * next WAL file.
 		 */
 		signal_child(PgArchPID, SIGUSR1);
 	}
diff --git a/src/bin/initdb/initdb.c b/src/bin/initdb/initdb.c
index 95da8b7722c..62aa40a5831 100644
--- a/src/bin/initdb/initdb.c
+++ b/src/bin/initdb/initdb.c
@@ -563,19 +563,19 @@ exit_nicely(void)
 
 		if (made_new_xlogdir)
 		{
-			fprintf(stderr, _("%s: removing transaction log directory \"%s\"\n"),
+			fprintf(stderr, _("%s: removing WAL directory \"%s\"\n"),
 					progname, xlog_dir);
 			if (!rmtree(xlog_dir, true))
-				fprintf(stderr, _("%s: failed to remove transaction log directory\n"),
+				fprintf(stderr, _("%s: failed to remove WAL directory\n"),
 						progname);
 		}
 		else if (found_existing_xlogdir)
 		{
 			fprintf(stderr,
-			_("%s: removing contents of transaction log directory \"%s\"\n"),
+			_("%s: removing contents of WAL directory \"%s\"\n"),
 					progname, xlog_dir);
 			if (!rmtree(xlog_dir, false))
-				fprintf(stderr, _("%s: failed to remove contents of transaction log directory\n"),
+				fprintf(stderr, _("%s: failed to remove contents of WAL directory\n"),
 						progname);
 		}
 		/* otherwise died during startup, do nothing! */
@@ -589,7 +589,7 @@ exit_nicely(void)
 
 		if (made_new_xlogdir || found_existing_xlogdir)
 			fprintf(stderr,
-					_("%s: transaction log directory \"%s\" not removed at user's request\n"),
+					_("%s: WAL directory \"%s\" not removed at user's request\n"),
 					progname, xlog_dir);
 	}
 
@@ -2704,7 +2704,7 @@ create_data_directory(void)
 }
 
 
-/* Create transaction log directory, and symlink if required */
+/* Create WAL directory, and symlink if required */
 void
 create_xlog_or_symlink(void)
 {
@@ -2721,7 +2721,7 @@ create_xlog_or_symlink(void)
 		canonicalize_path(xlog_dir);
 		if (!is_absolute_path(xlog_dir))
 		{
-			fprintf(stderr, _("%s: transaction log directory location must be an absolute path\n"), progname);
+			fprintf(stderr, _("%s: WAL directory location must be an absolute path\n"), progname);
 			exit_nicely();
 		}
 
@@ -2775,8 +2775,8 @@ create_xlog_or_symlink(void)
 					warn_on_mount_point(ret);
 				else
 					fprintf(stderr,
-							_("If you want to store the transaction log there, either\n"
-							  "remove or empty the directory \"%s\".\n"),
+							_("If you want to store the WAL there, either remove or empty the directory\n"
+							  "\"%s\".\n"),
 							xlog_dir);
 				exit_nicely();
 
diff --git a/src/bin/pg_basebackup/pg_basebackup.c b/src/bin/pg_basebackup/pg_basebackup.c
index e2a2ebb30f9..c7ddfcbfdf1 100644
--- a/src/bin/pg_basebackup/pg_basebackup.c
+++ b/src/bin/pg_basebackup/pg_basebackup.c
@@ -174,19 +174,19 @@ cleanup_directories_atexit(void)
 
 		if (made_new_xlogdir)
 		{
-			fprintf(stderr, _("%s: removing transaction log directory \"%s\"\n"),
+			fprintf(stderr, _("%s: removing WAL directory \"%s\"\n"),
 					progname, xlog_dir);
 			if (!rmtree(xlog_dir, true))
-				fprintf(stderr, _("%s: failed to remove transaction log directory\n"),
+				fprintf(stderr, _("%s: failed to remove WAL directory\n"),
 						progname);
 		}
 		else if (found_existing_xlogdir)
 		{
 			fprintf(stderr,
-					_("%s: removing contents of transaction log directory \"%s\"\n"),
+					_("%s: removing contents of WAL directory \"%s\"\n"),
 					progname, xlog_dir);
 			if (!rmtree(xlog_dir, false))
-				fprintf(stderr, _("%s: failed to remove contents of transaction log directory\n"),
+				fprintf(stderr, _("%s: failed to remove contents of WAL directory\n"),
 						progname);
 		}
 	}
@@ -199,7 +199,7 @@ cleanup_directories_atexit(void)
 
 		if (made_new_xlogdir || found_existing_xlogdir)
 			fprintf(stderr,
-					_("%s: transaction log directory \"%s\" not removed at user's request\n"),
+					_("%s: WAL directory \"%s\" not removed at user's request\n"),
 					progname, xlog_dir);
 	}
 
@@ -341,7 +341,7 @@ usage(void)
 	  "                         relocate tablespace in OLDDIR to NEWDIR\n"));
 	printf(_("  -X, --wal-method=none|fetch|stream\n"
 			 "                         include required WAL files with specified method\n"));
-	printf(_("      --waldir=WALDIR    location for the transaction log directory\n"));
+	printf(_("      --waldir=WALDIR    location for the write-ahead log directory\n"));
 	printf(_("  -z, --gzip             compress tar output\n"));
 	printf(_("  -Z, --compress=0-9     compress tar output with given compression level\n"));
 	printf(_("\nGeneral options:\n"));
@@ -414,7 +414,7 @@ reached_end_position(XLogRecPtr segendpos, uint32 timeline,
 			if (sscanf(xlogend, "%X/%X", &hi, &lo) != 2)
 			{
 				fprintf(stderr,
-				  _("%s: could not parse transaction log location \"%s\"\n"),
+				  _("%s: could not parse write-ahead log location \"%s\"\n"),
 						progname, xlogend);
 				exit(1);
 			}
@@ -549,7 +549,7 @@ StartLogStreamer(char *startpos, uint32 timeline, char *sysidentifier)
 	if (sscanf(startpos, "%X/%X", &hi, &lo) != 2)
 	{
 		fprintf(stderr,
-				_("%s: could not parse transaction log location \"%s\"\n"),
+				_("%s: could not parse write-ahead log location \"%s\"\n"),
 				progname, startpos);
 		disconnect_and_exit(1);
 	}
@@ -1404,7 +1404,7 @@ ReceiveAndUnpackTarFile(PGconn *conn, PGresult *res, int rownum)
 						/*
 						 * When streaming WAL, pg_wal (or pg_xlog for pre-9.6
 						 * clusters) will have been created by the wal receiver
-						 * process. Also, when transaction log directory location
+						 * process. Also, when the WAL directory location
 						 * was specified, pg_wal (or pg_xlog) has already been
 						 * created as a symbolic link before starting the actual
 						 * backup. So just ignore creation failures on related
@@ -1817,7 +1817,7 @@ BaseBackup(void)
 	MemSet(xlogend, 0, sizeof(xlogend));
 
 	if (verbose && includewal != NO_WAL)
-		fprintf(stderr, _("%s: transaction log start point: %s on timeline %u\n"),
+		fprintf(stderr, _("%s: write-ahead log start point: %s on timeline %u\n"),
 				progname, xlogstart, starttli);
 
 	/*
@@ -1907,20 +1907,20 @@ BaseBackup(void)
 	if (PQresultStatus(res) != PGRES_TUPLES_OK)
 	{
 		fprintf(stderr,
-		 _("%s: could not get transaction log end position from server: %s"),
+		 _("%s: could not get write-ahead log end position from server: %s"),
 				progname, PQerrorMessage(conn));
 		disconnect_and_exit(1);
 	}
 	if (PQntuples(res) != 1)
 	{
 		fprintf(stderr,
-			 _("%s: no transaction log end position returned from server\n"),
+			 _("%s: no write-ahead log end position returned from server\n"),
 				progname);
 		disconnect_and_exit(1);
 	}
 	strlcpy(xlogend, PQgetvalue(res, 0, 0), sizeof(xlogend));
 	if (verbose && includewal != NO_WAL)
-		fprintf(stderr, _("%s: transaction log end point: %s\n"), progname, xlogend);
+		fprintf(stderr, _("%s: write-ahead log end point: %s\n"), progname, xlogend);
 	PQclear(res);
 
 	res = PQgetResult(conn);
@@ -1998,7 +1998,7 @@ BaseBackup(void)
 		if (sscanf(xlogend, "%X/%X", &hi, &lo) != 2)
 		{
 			fprintf(stderr,
-				  _("%s: could not parse transaction log location \"%s\"\n"),
+				  _("%s: could not parse write-ahead log location \"%s\"\n"),
 					progname, xlogend);
 			disconnect_and_exit(1);
 		}
@@ -2312,7 +2312,7 @@ main(int argc, char **argv)
 	if (format == 't' && includewal == STREAM_WAL && strcmp(basedir, "-") == 0)
 	{
 		fprintf(stderr,
-			_("%s: cannot stream transaction logs in tar mode to stdout\n"),
+			_("%s: cannot stream write-ahead logs in tar mode to stdout\n"),
 				progname);
 		fprintf(stderr, _("Try \"%s --help\" for more information.\n"),
 				progname);
@@ -2348,7 +2348,7 @@ main(int argc, char **argv)
 		if (format != 'p')
 		{
 			fprintf(stderr,
-					_("%s: transaction log directory location can only be specified in plain mode\n"),
+					_("%s: WAL directory location can only be specified in plain mode\n"),
 					progname);
 			fprintf(stderr, _("Try \"%s --help\" for more information.\n"),
 					progname);
@@ -2359,7 +2359,7 @@ main(int argc, char **argv)
 		canonicalize_path(xlog_dir);
 		if (!is_absolute_path(xlog_dir))
 		{
-			fprintf(stderr, _("%s: transaction log directory location must be "
+			fprintf(stderr, _("%s: WAL directory location must be "
 							  "an absolute path\n"), progname);
 			fprintf(stderr, _("Try \"%s --help\" for more information.\n"),
 					progname);
@@ -2393,7 +2393,7 @@ main(int argc, char **argv)
 		exit(1);
 	}
 
-	/* Create transaction log symlink, if required */
+	/* Create pg_wal symlink, if required */
 	if (strcmp(xlog_dir, "") != 0)
 	{
 		char	   *linkloc;
diff --git a/src/bin/pg_basebackup/pg_receivewal.c b/src/bin/pg_basebackup/pg_receivewal.c
index 09385c5cbfc..b11984b0881 100644
--- a/src/bin/pg_basebackup/pg_receivewal.c
+++ b/src/bin/pg_basebackup/pg_receivewal.c
@@ -1,6 +1,6 @@
 /*-------------------------------------------------------------------------
  *
- * pg_receivewal.c - receive streaming transaction log data and write it
+ * pg_receivewal.c - receive streaming WAL data and write it
  *					  to a local file.
  *
  * Author: Magnus Hagander <magnus@hagander.net>
@@ -71,18 +71,18 @@ static bool stop_streaming(XLogRecPtr segendpos, uint32 timeline,
 static void
 usage(void)
 {
-	printf(_("%s receives PostgreSQL streaming transaction logs.\n\n"),
+	printf(_("%s receives PostgreSQL streaming write-ahead logs.\n\n"),
 		   progname);
 	printf(_("Usage:\n"));
 	printf(_("  %s [OPTION]...\n"), progname);
 	printf(_("\nOptions:\n"));
-	printf(_("  -D, --directory=DIR    receive transaction log files into this directory\n"));
+	printf(_("  -D, --directory=DIR    receive write-ahead log files into this directory\n"));
 	printf(_("      --if-not-exists    do not error if slot already exists when creating a slot\n"));
 	printf(_("  -n, --no-loop          do not loop on connection lost\n"));
 	printf(_("  -s, --status-interval=SECS\n"
 			 "                         time between status packets sent to server (default: %d)\n"), (standby_message_timeout / 1000));
 	printf(_("  -S, --slot=SLOTNAME    replication slot to use\n"));
-	printf(_("      --synchronous      flush transaction log immediately after writing\n"));
+	printf(_("      --synchronous      flush write-ahead log immediately after writing\n"));
 	printf(_("  -v, --verbose          output verbose messages\n"));
 	printf(_("  -V, --version          output version information, then exit\n"));
 	printf(_("  -Z, --compress=0-9     compress logs with given compression level\n"));
diff --git a/src/bin/pg_basebackup/receivelog.c b/src/bin/pg_basebackup/receivelog.c
index c41bba28cdf..0f2845bbc25 100644
--- a/src/bin/pg_basebackup/receivelog.c
+++ b/src/bin/pg_basebackup/receivelog.c
@@ -1,6 +1,6 @@
 /*-------------------------------------------------------------------------
  *
- * receivelog.c - receive transaction log files using the streaming
+ * receivelog.c - receive WAL files using the streaming
  *				  replication protocol.
  *
  * Author: Magnus Hagander <magnus@hagander.net>
@@ -116,7 +116,7 @@ open_walfile(StreamCtl *stream, XLogRecPtr startpoint)
 		if (size < 0)
 		{
 			fprintf(stderr,
-			_("%s: could not get size of transaction log file \"%s\": %s\n"),
+			_("%s: could not get size of write-ahead log file \"%s\": %s\n"),
 					progname, fn, stream->walmethod->getlasterror());
 			return false;
 		}
@@ -127,7 +127,7 @@ open_walfile(StreamCtl *stream, XLogRecPtr startpoint)
 			if (f == NULL)
 			{
 				fprintf(stderr,
-						_("%s: could not open existing transaction log file \"%s\": %s\n"),
+						_("%s: could not open existing write-ahead log file \"%s\": %s\n"),
 						progname, fn, stream->walmethod->getlasterror());
 				return false;
 			}
@@ -136,7 +136,7 @@ open_walfile(StreamCtl *stream, XLogRecPtr startpoint)
 			if (stream->walmethod->sync(f) != 0)
 			{
 				fprintf(stderr,
-						_("%s: could not sync existing transaction log file \"%s\": %s\n"),
+						_("%s: could not sync existing write-ahead log file \"%s\": %s\n"),
 						progname, fn, stream->walmethod->getlasterror());
 				stream->walmethod->close(f, CLOSE_UNLINK);
 				return false;
@@ -151,7 +151,7 @@ open_walfile(StreamCtl *stream, XLogRecPtr startpoint)
 			if (errno == 0)
 				errno = ENOSPC;
 			fprintf(stderr,
-					_("%s: transaction log file \"%s\" has %d bytes, should be 0 or %d\n"),
+					_("%s: write-ahead log file \"%s\" has %d bytes, should be 0 or %d\n"),
 					progname, fn, (int) size, XLogSegSize);
 			return false;
 		}
@@ -164,7 +164,7 @@ open_walfile(StreamCtl *stream, XLogRecPtr startpoint)
 	if (f == NULL)
 	{
 		fprintf(stderr,
-				_("%s: could not open transaction log file \"%s\": %s\n"),
+				_("%s: could not open write-ahead log file \"%s\": %s\n"),
 				progname, fn, stream->walmethod->getlasterror());
 		return false;
 	}
@@ -1121,7 +1121,7 @@ ProcessXLogDataMsg(PGconn *conn, StreamCtl *stream, char *copybuf, int len,
 		if (xlogoff != 0)
 		{
 			fprintf(stderr,
-					_("%s: received transaction log record for offset %u with no file open\n"),
+					_("%s: received write-ahead log record for offset %u with no file open\n"),
 					progname, xlogoff);
 			return false;
 		}
diff --git a/src/bin/pg_basebackup/streamutil.c b/src/bin/pg_basebackup/streamutil.c
index 1f2b4068d53..7ea3b0f8ee7 100644
--- a/src/bin/pg_basebackup/streamutil.c
+++ b/src/bin/pg_basebackup/streamutil.c
@@ -282,7 +282,7 @@ RunIdentifySystem(PGconn *conn, char **sysid, TimeLineID *starttli,
 		if (sscanf(PQgetvalue(res, 0, 2), "%X/%X", &hi, &lo) != 2)
 		{
 			fprintf(stderr,
-				  _("%s: could not parse transaction log location \"%s\"\n"),
+				  _("%s: could not parse write-ahead log location \"%s\"\n"),
 					progname, PQgetvalue(res, 0, 2));
 
 			PQclear(res);
diff --git a/src/bin/pg_resetwal/pg_resetwal.c b/src/bin/pg_resetwal/pg_resetwal.c
index 73bd9fe6ecb..9c3a28beb01 100644
--- a/src/bin/pg_resetwal/pg_resetwal.c
+++ b/src/bin/pg_resetwal/pg_resetwal.c
@@ -434,7 +434,7 @@ main(int argc, char *argv[])
 	if (ControlFile.state != DB_SHUTDOWNED && !force)
 	{
 		printf(_("The database server was not shut down cleanly.\n"
-			   "Resetting the transaction log might cause data to be lost.\n"
+			   "Resetting the write-ahead log might cause data to be lost.\n"
 				 "If you want to proceed anyway, use -f to force reset.\n"));
 		exit(1);
 	}
@@ -447,7 +447,7 @@ main(int argc, char *argv[])
 	KillExistingArchiveStatus();
 	WriteEmptyXLOG();
 
-	printf(_("Transaction log reset\n"));
+	printf(_("Write-ahead log reset\n"));
 	return 0;
 }
 
@@ -1159,7 +1159,7 @@ WriteEmptyXLOG(void)
 static void
 usage(void)
 {
-	printf(_("%s resets the PostgreSQL transaction log.\n\n"), progname);
+	printf(_("%s resets the PostgreSQL write-ahead log.\n\n"), progname);
 	printf(_("Usage:\n  %s [OPTION]... DATADIR\n\n"), progname);
 	printf(_("Options:\n"));
 	printf(_("  -c XID,XID       set oldest and newest transactions bearing commit timestamp\n"));
@@ -1167,7 +1167,7 @@ usage(void)
 	printf(_(" [-D] DATADIR      data directory\n"));
 	printf(_("  -e XIDEPOCH      set next transaction ID epoch\n"));
 	printf(_("  -f               force update to be done\n"));
-	printf(_("  -l XLOGFILE      force minimum WAL starting location for new transaction log\n"));
+	printf(_("  -l WALFILE       force minimum WAL starting location for new write-ahead log\n"));
 	printf(_("  -m MXID,MXID     set next and oldest multitransaction ID\n"));
 	printf(_("  -n               no update, just show what would be done (for testing)\n"));
 	printf(_("  -o OID           set next OID\n"));
diff --git a/src/bin/pg_rewind/timeline.c b/src/bin/pg_rewind/timeline.c
index f1a792ff6b2..3cd5af57f2a 100644
--- a/src/bin/pg_rewind/timeline.c
+++ b/src/bin/pg_rewind/timeline.c
@@ -80,7 +80,7 @@ rewind_parseTimeLineHistory(char *buffer, TimeLineID targetTLI, int *nentries)
 		if (nfields != 3)
 		{
 			fprintf(stderr, _("syntax error in history file: %s\n"), fline);
-			fprintf(stderr, _("Expected a transaction log switchpoint location.\n"));
+			fprintf(stderr, _("Expected a write-ahead log switchpoint location.\n"));
 			exit(1);
 		}
 		if (entries && tli <= lasttli)
diff --git a/src/bin/pg_waldump/pg_waldump.c b/src/bin/pg_waldump/pg_waldump.c
index 80c2c33ecb2..9491ccb13b9 100644
--- a/src/bin/pg_waldump/pg_waldump.c
+++ b/src/bin/pg_waldump/pg_waldump.c
@@ -680,7 +680,7 @@ XLogDumpDisplayStats(XLogDumpConfig *config, XLogDumpStats *stats)
 static void
 usage(void)
 {
-	printf(_("%s decodes and displays PostgreSQL transaction logs for debugging.\n\n"),
+	printf(_("%s decodes and displays PostgreSQL write-ahead logs for debugging.\n\n"),
 		   progname);
 	printf(_("Usage:\n"));
 	printf(_("  %s [OPTION]... [STARTSEG [ENDSEG]]\n"), progname);
diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h
index d23aab589e3..4d9773459de 100644
--- a/src/include/access/xlog.h
+++ b/src/include/access/xlog.h
@@ -1,7 +1,7 @@
 /*
  * xlog.h
  *
- * PostgreSQL transaction log manager
+ * PostgreSQL write-ahead log manager
  *
  * Portions Copyright (c) 1996-2017, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
diff --git a/src/include/access/xlog_internal.h b/src/include/access/xlog_internal.h
index c09c0f8e5f4..6e2bfd0ad03 100644
--- a/src/include/access/xlog_internal.h
+++ b/src/include/access/xlog_internal.h
@@ -1,7 +1,7 @@
 /*
  * xlog_internal.h
  *
- * PostgreSQL transaction log internal declarations
+ * PostgreSQL write-ahead log internal declarations
  *
  * NOTE: this file is intended to contain declarations useful for
  * manipulating the XLOG files directly, but it is not supposed to be
diff --git a/src/include/access/xlogdefs.h b/src/include/access/xlogdefs.h
index 53b60c1dcda..0f07bb26746 100644
--- a/src/include/access/xlogdefs.h
+++ b/src/include/access/xlogdefs.h
@@ -1,7 +1,7 @@
 /*
  * xlogdefs.h
  *
- * Postgres transaction log manager record pointer and
+ * Postgres write-ahead log manager record pointer and
  * timeline number definitions
  *
  * Portions Copyright (c) 1996-2017, PostgreSQL Global Development Group
diff --git a/src/test/perl/PostgresNode.pm b/src/test/perl/PostgresNode.pm
index e2274681b10..61d2c5fdf5d 100644
--- a/src/test/perl/PostgresNode.pm
+++ b/src/test/perl/PostgresNode.pm
@@ -483,7 +483,7 @@ sub append_conf
 =item $node->backup(backup_name)
 
 Create a hot backup with B<pg_basebackup> in subdirectory B<backup_name> of
-B<< $node->backup_dir >>, including the transaction logs. Transaction logs are
+B<< $node->backup_dir >>, including the WAL. WAL files
 fetched at the end of the backup, not streamed.
 
 You'll have to configure a suitable B<max_wal_senders> on the
@@ -507,7 +507,7 @@ sub backup
 =item $node->backup_fs_hot(backup_name)
 
 Create a backup with a filesystem level copy in subdirectory B<backup_name> of
-B<< $node->backup_dir >>, including transaction logs.
+B<< $node->backup_dir >>, including WAL.
 
 Archiving must be enabled, as B<pg_start_backup()> and B<pg_stop_backup()> are
 used. This is not checked or enforced.
@@ -525,7 +525,7 @@ sub backup_fs_hot
 =item $node->backup_fs_cold(backup_name)
 
 Create a backup with a filesystem level copy in subdirectory B<backup_name> of
-B<< $node->backup_dir >>, including transaction logs. The server must be
+B<< $node->backup_dir >>, including WAL. The server must be
 stopped as no attempt to handle concurrent writes is made.
 
 Use B<backup> or B<backup_fs_hot> if you want to back up a running server.