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.

doc/src/sgml/backup.sgml

@@ -1424,7 +1424,7 @@ restore_command = 'cp /mnt/server/archivedir/%f %p'
       As with base backups, the easiest way to produce a standalone
       hot backup is to use the <xref linkend="app-pgbasebackup">
       tool. If you include the <literal>-X</> parameter when calling
-      it, all the transaction log required to use the backup will be
+      it, all the write-ahead log required to use the backup will be
       included in the backup automatically, and no special action is
       required to restore the backup.
      </para>

doc/src/sgml/config.sgml

@@ -3312,7 +3312,7 @@ ANY <replaceable class="parameter">num_sync</replaceable> ( <replaceable class="
        to the primary or upstream standby, where it can be seen using the
        <link linkend="monitoring-stats-views-table">
        <literal>pg_stat_replication</></link> view.  The standby will report
-       the last transaction log position it has written, the last position it
+       the last write-ahead log position it has written, the last position it
        has flushed to disk, and the last position it has applied.
        This parameter's
        value is the maximum interval, in seconds, between reports.  Updates are

doc/src/sgml/high-availability.sgml

@@ -138,7 +138,7 @@ protocol to make nodes agree on a serializable transactional order.
   </varlistentry>
 
   <varlistentry>
-   <term>Transaction Log Shipping</term>
+   <term>Write-Ahead Log Shipping</term>
    <listitem>
 
     <para>
@@ -289,7 +289,7 @@ protocol to make nodes agree on a serializable transactional order.
      <entry>Feature</entry>
      <entry>Shared Disk Failover</entry>
      <entry>File System Replication</entry>
-     <entry>Transaction Log Shipping</entry>
+     <entry>Write-Ahead Log Shipping</entry>
      <entry>Trigger-Based Master-Standby Replication</entry>
      <entry>Statement-Based Replication Middleware</entry>
      <entry>Asynchronous Multimaster Replication</entry>
@@ -1036,7 +1036,7 @@ primary_slot_name = 'node_a_slot'
    <para>
     When requesting synchronous replication, each commit of a
     write transaction will wait until confirmation is
-    received that the commit has been written to the transaction log on disk
+    received that the commit has been written to the write-ahead log on disk
     of both the primary and standby server. The only possibility that data
     can be lost is if both the primary and the standby suffer crashes at the
     same time. This can provide a much higher level of durability, though only

doc/src/sgml/monitoring.sgml

@@ -1032,7 +1032,7 @@ postgres   27093  0.0  0.0  30096  2752 ?        Ss   11:34   0:00 postgres: ser
         </row>
         <row>
          <entry><literal>CLogTruncationLock</></entry>
-         <entry>Waiting to truncate the transaction log or waiting for transaction log truncation to finish.</entry>
+         <entry>Waiting to truncate the write-ahead log or waiting for write-ahead log truncation to finish.</entry>
         </row>
         <row>
          <entry><literal>clog</></entry>
@@ -1701,24 +1701,24 @@ SELECT pid, wait_event_type, wait_event FROM pg_stat_activity WHERE wait_event i
     <row>
      <entry><structfield>sent_lsn</></entry>
      <entry><type>pg_lsn</></entry>
-     <entry>Last transaction log location sent on this connection</entry>
+     <entry>Last write-ahead log location sent on this connection</entry>
     </row>
     <row>
      <entry><structfield>write_lsn</></entry>
      <entry><type>pg_lsn</></entry>
-     <entry>Last transaction log location written to disk by this standby
+     <entry>Last write-ahead log location written to disk by this standby
       server</entry>
     </row>
     <row>
      <entry><structfield>flush_lsn</></entry>
      <entry><type>pg_lsn</></entry>
-     <entry>Last transaction log location flushed to disk by this standby
+     <entry>Last write-ahead log location flushed to disk by this standby
       server</entry>
     </row>
     <row>
      <entry><structfield>replay_lsn</></entry>
      <entry><type>pg_lsn</></entry>
-     <entry>Last transaction log location replayed into the database on this
+     <entry>Last write-ahead log location replayed into the database on this
       standby server</entry>
     </row>
     <row>
@@ -1865,7 +1865,7 @@ SELECT pid, wait_event_type, wait_event FROM pg_stat_activity WHERE wait_event i
     <row>
      <entry><structfield>receive_start_lsn</></entry>
      <entry><type>pg_lsn</></entry>
-     <entry>First transaction log position used when WAL receiver is
+     <entry>First write-ahead log position used when WAL receiver is
       started</entry>
     </row>
     <row>
@@ -1876,14 +1876,14 @@ SELECT pid, wait_event_type, wait_event FROM pg_stat_activity WHERE wait_event i
     <row>
      <entry><structfield>received_lsn</></entry>
      <entry><type>pg_lsn</></entry>
-     <entry>Last transaction log position already received and flushed to
+     <entry>Last write-ahead log position already received and flushed to
       disk, the initial value of this field being the first log position used
       when WAL receiver is started</entry>
     </row>
     <row>
      <entry><structfield>received_tli</></entry>
      <entry><type>integer</></entry>
-     <entry>Timeline number of last transaction log position received and
+     <entry>Timeline number of last write-ahead log position received and
       flushed to disk, the initial value of this field being the timeline
       number of the first log position used when WAL receiver is started
      </entry>
@@ -1901,12 +1901,12 @@ SELECT pid, wait_event_type, wait_event FROM pg_stat_activity WHERE wait_event i
     <row>
      <entry><structfield>latest_end_lsn</></entry>
      <entry><type>pg_lsn</></entry>
-     <entry>Last transaction log position reported to origin WAL sender</entry>
+     <entry>Last write-ahead log position reported to origin WAL sender</entry>
     </row>
     <row>
      <entry><structfield>latest_end_time</></entry>
      <entry><type>timestamp with time zone</></entry>
-     <entry>Time of last transaction log position reported to origin WAL sender</entry>
+     <entry>Time of last write-ahead log position reported to origin WAL sender</entry>
     </row>
     <row>
      <entry><structfield>slot_name</></entry>
@@ -1967,7 +1967,7 @@ SELECT pid, wait_event_type, wait_event FROM pg_stat_activity WHERE wait_event i
     <row>
      <entry><structfield>received_lsn</></entry>
      <entry><type>pg_lsn</></entry>
-     <entry>Last transaction log position received, the initial value of
+     <entry>Last write-ahead log position received, the initial value of
       this field being 0</entry>
     </row>
     <row>
@@ -1984,13 +1984,13 @@ SELECT pid, wait_event_type, wait_event FROM pg_stat_activity WHERE wait_event i
     <row>
      <entry><structfield>latest_end_lsn</></entry>
      <entry><type>pg_lsn</></entry>
-     <entry>Last transaction log position reported to origin WAL sender
+     <entry>Last write-ahead log position reported to origin WAL sender
      </entry>
     </row>
     <row>
      <entry><structfield>latest_end_time</></entry>
      <entry><type>timestamp with time zone</></entry>
-     <entry>Time of last transaction log position reported to origin WAL
+     <entry>Time of last write-ahead log position reported to origin WAL
       sender</entry>
     </row>
    </tbody>

doc/src/sgml/protocol.sgml

@@ -1547,7 +1547,7 @@ The commands accepted in walsender mode are:
       <listitem>
       <para>
        Current WAL flush location. Useful to get a known location in the
-       transaction log where streaming can start.
+       write-ahead log where streaming can start.
       </para>
       </listitem>
       </varlistentry>

doc/src/sgml/recovery-config.sgml

@@ -242,7 +242,7 @@ restore_command = 'copy "C:\\server\\archivedir\\%f" "%p"'  # Windows
       </term>
       <listitem>
        <para>
-        This parameter specifies the LSN of the transaction log location up
+        This parameter specifies the LSN of the write-ahead log location up
         to which recovery will proceed. The precise stopping point is also
         influenced by <xref linkend="recovery-target-inclusive">. This
         parameter is parsed using the system data type

doc/src/sgml/ref/checkpoint.sgml

@@ -13,7 +13,7 @@
 
  <refnamediv>
   <refname>CHECKPOINT</refname>
-  <refpurpose>force a transaction log checkpoint</refpurpose>
+  <refpurpose>force a write-ahead log checkpoint</refpurpose>
  </refnamediv>
 
  <refsynopsisdiv>
@@ -26,7 +26,7 @@ CHECKPOINT
   <title>Description</title>
 
   <para>
-   A checkpoint is a point in the transaction log sequence at which
+   A checkpoint is a point in the write-ahead log sequence at which
    all data files have been updated to reflect the information in the
    log.  All data files will be flushed to disk.  Refer to
    <xref linkend="wal-configuration"> for more details about what happens

doc/src/sgml/ref/initdb.sgml

@@ -320,7 +320,7 @@ PostgreSQL documentation
       <term><option>--waldir=<replaceable class="parameter">directory</replaceable></option></term>
       <listitem>
        <para>
-        This option specifies the directory where the transaction log
+        This option specifies the directory where the write-ahead log
         should be stored.
        </para>
       </listitem>

doc/src/sgml/ref/pg_basebackup.sgml

@@ -178,8 +178,8 @@ PostgreSQL documentation
             target directory, the tar contents will be written to
             standard output, suitable for piping to for example
             <productname>gzip</productname>. This is only possible if
-            the cluster has no additional tablespaces and transaction
-            log streaming is not used.
+            the cluster has no additional tablespaces and WAL
+            streaming is not used.
            </para>
            </listitem>
          </varlistentry>
@@ -299,9 +299,9 @@ PostgreSQL documentation
       <term><option>--waldir=<replaceable class="parameter">waldir</replaceable></option></term>
       <listitem>
        <para>
-        Specifies the location for the transaction log directory.
+        Specifies the location for the write-ahead log directory.
         <replaceable>waldir</replaceable> must be an absolute path.
-        The transaction log directory can only be specified when
+        The write-ahead log directory can only be specified when
         the backup is in plain mode.
        </para>
       </listitem>
@@ -312,15 +312,15 @@ PostgreSQL documentation
       <term><option>--wal-method=<replaceable class="parameter">method</replaceable></option></term>
       <listitem>
        <para>
-        Includes the required transaction log files (WAL files) in the
-        backup. This will include all transaction logs generated during
+        Includes the required write-ahead log files (WAL files) in the
+        backup. This will include all write-ahead logs generated during
         the backup. Unless the method <literal>none</literal> is specified,
         it is possible to start a postmaster directly in the extracted
         directory without the need to consult the log archive, thus
         making this a completely standalone backup.
        </para>
        <para>
-        The following methods for collecting the transaction logs are
+        The following methods for collecting the write-ahead logs are
         supported:
 
         <variablelist>
@@ -329,7 +329,7 @@ PostgreSQL documentation
           <term><literal>none</literal></term>
           <listitem>
            <para>
-            Don't include transaction log in the backup.
+            Don't include write-ahead log in the backup.
            </para>
           </listitem>
          </varlistentry>
@@ -339,7 +339,7 @@ PostgreSQL documentation
           <term><literal>fetch</literal></term>
           <listitem>
            <para>
-            The transaction log files are collected at the end of the backup.
+            The write-ahead log files are collected at the end of the backup.
             Therefore, it is necessary for the
             <xref linkend="guc-wal-keep-segments"> parameter to be set high
              enough that the log is not removed before the end of the backup.
@@ -347,7 +347,7 @@ PostgreSQL documentation
              backup will fail and be unusable.
            </para>
            <para>
-            The transaction log files will be written to
+            The write-ahead log files will be written to
             the <filename>base.tar</filename> file.
            </para>
           </listitem>
@@ -358,16 +358,16 @@ PostgreSQL documentation
           <term><literal>stream</literal></term>
           <listitem>
            <para>
-            Stream the transaction log while the backup is created. This will
+            Stream the write-ahead log while the backup is created. This will
             open a second connection to the server and start streaming the
-            transaction log in parallel while running the backup. Therefore,
+            write-ahead log in parallel while running the backup. Therefore,
             it will use up two connections configured by the
             <xref linkend="guc-max-wal-senders"> parameter. As long as the
-             client can keep up with transaction log received, using this mode
-             requires no extra transaction logs to be saved on the master.
+             client can keep up with write-ahead log received, using this mode
+             requires no extra write-ahead logs to be saved on the master.
            </para>
            <para>
-            The transaction log files are written to a separate file
+            The write-ahead log files are written to a separate file
             named <filename>pg_wal.tar</filename> (if the server is a version
             earlier than 10, the file will be named <filename>pg_xlog.tar</filename>).
            </para>
@@ -443,7 +443,7 @@ PostgreSQL documentation
         By default, when <command>pg_basebackup</command> aborts with an
         error, it removes any directories it might have created before
         discovering that it cannot finish the job (for example, data directory
-        and transaction log directory). This option inhibits tidying-up and is
+        and write-ahead log directory). This option inhibits tidying-up and is
         thus useful for debugging.
        </para>
 

doc/src/sgml/ref/pg_receivewal.sgml

@@ -16,7 +16,7 @@ PostgreSQL documentation
 
  <refnamediv>
   <refname>pg_receivewal</refname>
-  <refpurpose>stream transaction logs from a <productname>PostgreSQL</productname> server</refpurpose>
+  <refpurpose>stream write-ahead logs from a <productname>PostgreSQL</productname> server</refpurpose>
  </refnamediv>
 
  <refsynopsisdiv>
@@ -31,8 +31,8 @@ PostgreSQL documentation
    Description
   </title>
   <para>
-   <application>pg_receivewal</application> is used to stream the transaction log
-   from a running <productname>PostgreSQL</productname> cluster. The transaction
+   <application>pg_receivewal</application> is used to stream the write-ahead log
+   from a running <productname>PostgreSQL</productname> cluster. The write-ahead
    log is streamed using the streaming replication protocol, and is written
    to a local directory of files. This directory can be used as the archive
    location for doing a restore using point-in-time recovery (see
@@ -40,7 +40,7 @@ PostgreSQL documentation
   </para>
 
   <para>
-   <application>pg_receivewal</application> streams the transaction
+   <application>pg_receivewal</application> streams the write-ahead
    log in real time as it's being generated on the server, and does not wait
    for segments to complete like <xref linkend="guc-archive-command"> does.
    For this reason, it is not necessary to set
@@ -56,7 +56,7 @@ PostgreSQL documentation
   </para>
 
   <para>
-   The transaction log is streamed over a regular
+   The write-ahead log is streamed over a regular
    <productname>PostgreSQL</productname> connection and uses the replication
    protocol. The connection must be made with a superuser or a user
    having <literal>REPLICATION</literal> permissions (see
@@ -186,7 +186,7 @@ PostgreSQL documentation
       <term><option>--compress=<replaceable class="parameter">level</replaceable></option></term>
       <listitem>
        <para>
-        Enables gzip compression of transaction logs, and specifies the
+        Enables gzip compression of write-ahead logs, and specifies the
         compression level (0 through 9, 0 being no compression and 9 being best
         compression).  The suffix <filename>.gz</filename> will
         automatically be added to all filenames.
@@ -366,7 +366,7 @@ PostgreSQL documentation
    When using <application>pg_receivewal</application> instead of
    <xref linkend="guc-archive-command"> as the main WAL backup method, it is
    strongly recommended to use replication slots.  Otherwise, the server is
-   free to recycle or remove transaction log files before they are backed up,
+   free to recycle or remove write-ahead log files before they are backed up,
    because it does not have any information, either
    from <xref linkend="guc-archive-command"> or the replication slots, about
    how far the WAL stream has been archived.  Note, however, that a
@@ -380,7 +380,7 @@ PostgreSQL documentation
   <title>Examples</title>
 
   <para>
-   To stream the transaction log from the server at
+   To stream the write-ahead log from the server at
    <literal>mydbserver</literal> and store it in the local directory
    <filename>/usr/local/pgsql/archive</filename>:
 <screen>

doc/src/sgml/ref/pgbench.sgml

@@ -614,7 +614,7 @@ pgbench <optional> <replaceable>options</> </optional> <replaceable>dbname</>
       <term><option>--log-prefix=<replaceable>prefix</></option></term>
       <listitem>
        <para>
-        Set the filename prefix for the transaction log files created by
+        Set the filename prefix for the log files created by
         <option>--log</>.  The default is <literal>pgbench_log</>.
        </para>
       </listitem>

doc/src/sgml/ref/pgtestfsync.sgml

@@ -34,7 +34,7 @@
   problem.  However, differences shown by
   <application>pg_test_fsync</application> might not make any significant
   difference in real database throughput, especially since many database servers
-  are not speed-limited by their transaction logs.
+  are not speed-limited by their write-ahead logs.
   <application>pg_test_fsync</application> reports average file sync operation
   time in microseconds for each <literal>wal_sync_method</literal>, which can also be used to
   inform efforts to optimize the value of <xref linkend="guc-commit-delay">.

doc/src/sgml/release-10.sgml

@@ -2517,7 +2517,7 @@
        2016-12-21 [ecbdc4c55] Forbid invalid combination of options in pg_basebackup.
        -->
        <para>
-        Allow <application>pg_basebackup</> to stream transaction log in
+        Allow <application>pg_basebackup</> to stream write-ahead log in
         tar mode (Magnus Hagander)
        </para>
 

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,

src/backend/access/transam/transam.c

 /*-------------------------------------------------------------------------
  *
  * 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

src/backend/access/transam/xlog.c

 /*-------------------------------------------------------------------------
  *
  * 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

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.
  *

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.

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);
 		}
 
 		/*

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);

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);
 	}

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();
 

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;

src/bin/pg_basebackup/pg_receivewal.c

 /*-------------------------------------------------------------------------
  *
- * 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"));

src/bin/pg_basebackup/receivelog.c

 /*-------------------------------------------------------------------------
  *
- * 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;
 		}

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);

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"));

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)

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);

src/include/access/xlog.h

 /*
  * 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

src/include/access/xlog_internal.h

 /*
  * 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

src/include/access/xlogdefs.h

 /*
  * 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

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.