diff --git a/admin/include/functions_history.inc.php b/admin/include/functions_history.inc.php
index 55783fd74..f0156c025 100644
--- a/admin/include/functions_history.inc.php
+++ b/admin/include/functions_history.inc.php
@@ -176,6 +176,310 @@ SELECT
   return $data;
 }
 
+/**
+ * Compute statistics from history table to history_summary table
+ *
+ * @param int $max_lines - to only compute the next X lines, not the whole remaining lines
+ */
+function history_summarize($max_lines=null)
+{
+  // we need to know which was the last line "summarized"
+  $query = '
+SELECT
+    *
+  FROM '.HISTORY_SUMMARY_TABLE.'
+  WHERE history_id_to IS NOT NULL
+  ORDER BY history_id_to DESC
+  LIMIT 1
+;';
+  $summary_lines = query2array($query);
+
+  $history_min_id = 0;
+  if (count($summary_lines) > 0)
+  {
+    $last_summary = $summary_lines[0];
+    $history_min_id = $last_summary['history_id_to'];
+  }
+  else
+  {
+    // if we have no "reference", ie "starting point", we need to find
+    // one. And "0" is not the right answer here, because history table may
+    // have been purged already.
+    $query = '
+SELECT
+    MIN(id) AS min_id
+  FROM '.HISTORY_TABLE.'
+;';
+    $history_lines = query2array($query);
+    if (count($history_lines) > 0)
+    {
+      $history_min_id = $history_lines[0]['min_id'] - 1;
+    }
+  }
+
+  $query = '
+SELECT
+    date,
+    '.pwg_db_get_hour('time').' AS hour,
+    MIN(id) AS min_id,
+    MAX(id) AS max_id,
+    COUNT(*) AS nb_pages
+  FROM '.HISTORY_TABLE.'
+  WHERE id > '.$history_min_id;
+
+  if (isset($max_lines))
+  {
+    $query.= '
+    AND id <= '.($history_min_id + $max_lines);
+  }
+
+  $query.= '
+  GROUP BY
+    date,
+    hour
+  ORDER BY
+    date ASC,
+    hour ASC
+;';
+  $result = pwg_query($query);
+
+  $need_update = array();
+
+  $is_first = true;
+  $first_time_key = null;
+
+  while ($row = pwg_db_fetch_assoc($result))
+  {
+    $time_keys = array(
+      substr($row['date'], 0, 4), //yyyy
+      substr($row['date'], 0, 7), //yyyy-mm
+      substr($row['date'], 0, 10),//yyyy-mm-dd
+      sprintf(
+        '%s-%02u',
+        $row['date'], $row['hour']
+        ),
+      );
+
+    foreach ($time_keys as $time_key)
+    {
+      if (!isset($need_update[$time_key]))
+      {
+        $need_update[$time_key] = array(
+          'nb_pages' => 0,
+          'history_id_from' => $row['min_id'],
+          'history_id_to' => $row['max_id'],
+          );
+      }
+      $need_update[$time_key]['nb_pages'] += $row['nb_pages'];
+
+      if ($row['min_id'] < $need_update[$time_key]['history_id_from'])
+      {
+        $need_update[$time_key]['history_id_from'] = $row['min_id'];
+      }
+
+      if ($row['max_id'] > $need_update[$time_key]['history_id_to'])
+      {
+        $need_update[$time_key]['history_id_to'] = $row['max_id'];
+      }
+    }
+
+    if ($is_first)
+    {
+      $is_first = false;
+      $first_time_key = $time_keys[3];
+    }
+  }
+
+// Only the oldest time_key might be already summarized, so we have to
+// update the 4 corresponding lines instead of simply inserting them.
+//
+// For example, if the oldest unsummarized is 2005.08.25.21, the 4 lines
+// that can be updated are:
+//
+// +---------------+----------+
+// | id            | nb_pages |
+// +---------------+----------+
+// | 2005          |   241109 |
+// | 2005-08       |    20133 |
+// | 2005-08-25    |      620 |
+// | 2005-08-25-21 |      151 |
+// +---------------+----------+
+
+  $updates = array();
+  $inserts = array();
+
+  if (isset($first_time_key))
+  {
+    list($year, $month, $day, $hour) = explode('-', $first_time_key);
+
+    $query = '
+SELECT *
+  FROM '.HISTORY_SUMMARY_TABLE.'
+  WHERE year='.$year.'
+    AND ( month IS NULL
+      OR ( month='.$month.'
+        AND ( day is NULL
+          OR (day='.$day.'
+            AND (hour IS NULL OR hour='.$hour.')
+          )
+        )
+      )
+    )
+;';
+    $result = pwg_query($query);
+    while ($row = pwg_db_fetch_assoc($result))
+    {
+      $key = sprintf('%4u', $row['year']);
+      if ( isset($row['month']) )
+      {
+        $key .= sprintf('-%02u', $row['month']);
+        if ( isset($row['day']) )
+        {
+          $key .= sprintf('-%02u', $row['day']);
+          if ( isset($row['hour']) )
+          {
+            $key .= sprintf('-%02u', $row['hour']);
+          }
+        }
+      }
+
+      if (isset($need_update[$key]))
+      {
+        $row['nb_pages'] += $need_update[$key]['nb_pages'];
+        $row['history_id_to'] = $need_update[$key]['history_id_to'];
+        $updates[] = $row;
+        unset($need_update[$key]);
+      }
+    }
+  }
+
+  foreach ($need_update as $time_key => $summary)
+  {
+    $time_tokens = explode('-', $time_key);
+
+    $inserts[] = array(
+      'year'     => $time_tokens[0],
+      'month'    => @$time_tokens[1],
+      'day'      => @$time_tokens[2],
+      'hour'     => @$time_tokens[3],
+      'nb_pages' => $summary['nb_pages'],
+      'history_id_from' => $summary['history_id_from'],
+      'history_id_to' => $summary['history_id_to'],
+      );
+  }
+
+  if (count($updates) > 0)
+  {
+    mass_updates(
+      HISTORY_SUMMARY_TABLE,
+      array(
+        'primary' => array('year','month','day','hour'),
+        'update'  => array('nb_pages','history_id_to'),
+        ),
+      $updates
+      );
+  }
+
+  if (count($inserts) > 0)
+  {
+    mass_inserts(
+      HISTORY_SUMMARY_TABLE,
+      array_keys($inserts[0]),
+      $inserts
+      );
+  }
+}
+
+/**
+ * Smart purge on history table. Keep some lines, purge only summarized lines
+ *
+ * @since 2.9
+ */
+function history_autopurge()
+{
+  global $conf, $logger;
+
+  if (0 == $conf['history_autopurge_keep_lines'])
+  {
+    return;
+  }
+
+  // we want to purge only if there are too many lines and if the lines are summarized
+
+  $query = '
+SELECT
+    COUNT(*)
+  FROM '.HISTORY_TABLE.'
+;';
+  list($count) = pwg_db_fetch_row(pwg_query($query));
+
+  if ($count <= $conf['history_autopurge_keep_lines'])
+  {
+    return; // no need to purge for now
+  }
+
+  // 1) find the last summarized history line
+  $query = '
+SELECT
+    *
+  FROM '.HISTORY_SUMMARY_TABLE.'
+  WHERE history_id_to IS NOT NULL
+  ORDER BY history_id_to DESC
+  LIMIT 1
+;';
+  $summary_lines = query2array($query);
+  if (count($summary_lines) == 0)
+  {
+    return; // lines not summarized, no purge
+  }
+
+  $history_id_last_summarized = $summary_lines[0]['history_id_to'];
+
+  // 2) find the latest history line (and substract the number of lines to keep)
+  $query = '
+SELECT
+    id
+  FROM '.HISTORY_TABLE.'
+  ORDER BY id DESC
+  LIMIT 1
+;';
+  $history_lines = query2array($query);
+  if (count($history_lines) == 0)
+  {
+    return;
+  }
+
+  $history_id_latest = $history_lines[0]['id'];
+
+  // 3) find the oldest history line (and add the number of lines to delete)
+  $query = '
+SELECT
+    id
+  FROM '.HISTORY_TABLE.'
+  ORDER BY id ASC
+  LIMIT 1
+;';
+  $history_lines = query2array($query);
+  $history_id_oldest = $history_lines[0]['id'];
+
+  $search_min = array(
+    $history_id_last_summarized,
+    $history_id_latest - $conf['history_autopurge_keep_lines'],
+    $history_id_oldest + $conf['history_autopurge_blocksize'],
+    );
+  
+  $history_id_delete_before = min($search_min);
+
+  $logger->debug(__FUNCTION__.', '.join('/', $search_min));
+
+  $query = '
+DELETE
+  FROM '.HISTORY_TABLE.'
+  WHERE id < '.$history_id_delete_before.'
+;';
+  pwg_query($query);
+}
+
 add_event_handler('get_history', 'get_history');
 trigger_notify('functions_history_included');
 
diff --git a/admin/stats.php b/admin/stats.php
index 5398d0b26..6115fecec 100644
--- a/admin/stats.php
+++ b/admin/stats.php
@@ -113,169 +113,7 @@ check_status(ACCESS_ADMINISTRATOR);
 // | Refresh summary from details                                          |
 // +-----------------------------------------------------------------------+
 
-$query = '
-SELECT
-    date,
-    '.pwg_db_get_hour('time').' AS hour,
-    MAX(id) AS max_id,
-    COUNT(*) AS nb_pages
-  FROM '.HISTORY_TABLE.'
-  WHERE summarized = \'false\'
-  GROUP BY
-    date,
-    hour
-  ORDER BY
-    date ASC,
-    hour ASC
-;';
-$result = pwg_query($query);
-
-$need_update = array();
-
-$max_id = 0;
-$is_first = true;
-$first_time_key = null;
-
-while ($row = pwg_db_fetch_assoc($result))
-{
-  $time_keys = array(
-    substr($row['date'], 0, 4), //yyyy
-    substr($row['date'], 0, 7), //yyyy-mm
-    substr($row['date'], 0, 10),//yyyy-mm-dd
-    sprintf(
-      '%s-%02u',
-      $row['date'], $row['hour']
-      ),
-    );
-
-  foreach ($time_keys as $time_key)
-  {
-    if (!isset($need_update[$time_key]))
-    {
-      $need_update[$time_key] = 0;
-    }
-    $need_update[$time_key] += $row['nb_pages'];
-  }
-
-  if ($row['max_id'] > $max_id)
-  {
-    $max_id = $row['max_id'];
-  }
-
-  if ($is_first)
-  {
-    $is_first = false;
-    $first_time_key = $time_keys[3];
-  }
-}
-
-// Only the oldest time_key might be already summarized, so we have to
-// update the 4 corresponding lines instead of simply inserting them.
-//
-// For example, if the oldest unsummarized is 2005.08.25.21, the 4 lines
-// that can be updated are:
-//
-// +---------------+----------+
-// | id            | nb_pages |
-// +---------------+----------+
-// | 2005          |   241109 |
-// | 2005-08       |    20133 |
-// | 2005-08-25    |      620 |
-// | 2005-08-25-21 |      151 |
-// +---------------+----------+
-
-
-$updates = array();
-$inserts = array();
-
-if (isset($first_time_key))
-{
-  list($year, $month, $day, $hour) = explode('-', $first_time_key);
-
-  $query = '
-SELECT *
-  FROM '.HISTORY_SUMMARY_TABLE.'
-  WHERE year='.$year.'
-    AND ( month IS NULL
-      OR ( month='.$month.'
-        AND ( day is NULL 
-          OR (day='.$day.'
-            AND (hour IS NULL OR hour='.$hour.')
-          )
-        )
-      )
-    )
-;';
-  $result = pwg_query($query);
-  while ($row = pwg_db_fetch_assoc($result))
-  {
-    $key = sprintf('%4u', $row['year']);
-    if ( isset($row['month']) )
-    {
-      $key .= sprintf('-%02u', $row['month']);
-      if ( isset($row['day']) )
-      {
-        $key .= sprintf('-%02u', $row['day']);
-        if ( isset($row['hour']) )
-        {
-          $key .= sprintf('-%02u', $row['hour']);
-        }
-      }
-    }
-
-    if (isset($need_update[$key]))
-    {
-      $row['nb_pages'] += $need_update[$key];
-      $updates[] = $row;
-      unset($need_update[$key]);
-    }
-  }
-}
-
-foreach ($need_update as $time_key => $nb_pages)
-{
-  $time_tokens = explode('-', $time_key);
-
-  $inserts[] = array(
-    'year'     => $time_tokens[0],
-    'month'    => @$time_tokens[1],
-    'day'      => @$time_tokens[2],
-    'hour'     => @$time_tokens[3],
-    'nb_pages' => $nb_pages,
-    );
-}
-
-if (count($updates) > 0)
-{
-  mass_updates(
-    HISTORY_SUMMARY_TABLE,
-    array(
-      'primary' => array('year','month','day','hour'),
-      'update'  => array('nb_pages'),
-      ),
-    $updates
-    );
-}
-
-if (count($inserts) > 0)
-{
-  mass_inserts(
-    HISTORY_SUMMARY_TABLE,
-    array_keys($inserts[0]),
-    $inserts
-    );
-}
-
-if ($max_id != 0)
-{
-  $query = '
-UPDATE '.HISTORY_TABLE.'
-  SET summarized = \'true\'
-  WHERE summarized = \'false\'
-    AND id <= '.$max_id.'
-;';
-  pwg_query($query);
-}
+history_summarize();
 
 // +-----------------------------------------------------------------------+
 // | Page parameters check                                                 |
diff --git a/include/config_default.inc.php b/include/config_default.inc.php
index 1f27362e7..c3b36064f 100644
--- a/include/config_default.inc.php
+++ b/include/config_default.inc.php
@@ -553,6 +553,16 @@ $conf['guest_access'] = true;
 // nb_logs_page :  how many logs to display on a page
 $conf['nb_logs_page'] = 300;
 
+// Every X new line in history, perform an automatic purge. The more often,
+// the fewer lines to delete. 0 to disable.
+$conf['history_autopurge_every'] = 1021;
+
+// How many lines to keep in history on autopurge? 0 to disable.
+$conf['history_autopurge_keep_lines'] = 1000000;
+
+// On history autopurge, how many lines should to deleted at once, maximum?
+$conf['history_autopurge_blocksize'] = 50000;
+
 // +-----------------------------------------------------------------------+
 // |                                 urls                                  |
 // +-----------------------------------------------------------------------+
diff --git a/include/functions.inc.php b/include/functions.inc.php
index 7ed6a196f..cbc896e2f 100644
--- a/include/functions.inc.php
+++ b/include/functions.inc.php
@@ -495,6 +495,19 @@ INSERT INTO '.HISTORY_TABLE.'
 ;';
   pwg_query($query);
 
+  $history_id = pwg_db_insert_id(HISTORY_TABLE);
+  if ($history_id % 1000 == 0)
+  {
+    include_once(PHPWG_ROOT_PATH.'admin/include/functions_history.inc.php');
+    history_summarize(50000);
+  }
+
+  if ($conf['history_autopurge_every'] > 0 and $history_id % $conf['history_autopurge_every'] == 0)
+  {
+    include_once(PHPWG_ROOT_PATH.'admin/include/functions_history.inc.php');
+    history_autopurge();
+  }
+
   return true;
 }
 
diff --git a/install/db/150-database.php b/install/db/150-database.php
new file mode 100644
index 000000000..505a389cd
--- /dev/null
+++ b/install/db/150-database.php
@@ -0,0 +1,80 @@
+<?php
+// +-----------------------------------------------------------------------+
+// | Piwigo - a PHP based photo gallery                                    |
+// +-----------------------------------------------------------------------+
+// | Copyright(C) 2008-2016 Piwigo Team                  http://piwigo.org |
+// | Copyright(C) 2003-2008 PhpWebGallery Team    http://phpwebgallery.net |
+// | Copyright(C) 2002-2003 Pierrick LE GALL   http://le-gall.net/pierrick |
+// +-----------------------------------------------------------------------+
+// | This program is free software; you can redistribute it and/or modify  |
+// | it under the terms of the GNU General Public License as published by  |
+// | the Free Software Foundation                                          |
+// |                                                                       |
+// | This program is distributed in the hope that it will be useful, but   |
+// | WITHOUT ANY WARRANTY; without even the implied warranty of            |
+// | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU      |
+// | General Public License for more details.                              |
+// |                                                                       |
+// | You should have received a copy of the GNU General Public License     |
+// | along with this program; if not, write to the Free Software           |
+// | Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, |
+// | USA.                                                                  |
+// +-----------------------------------------------------------------------+
+
+if (!defined('PHPWG_ROOT_PATH'))
+{
+  die('Hacking attempt!');
+}
+
+$upgrade_description = 'add history_id_from+history_id_to in history_summary table';
+
+// we use PREFIX_TABLE, in case Piwigo uses an external user table
+pwg_query('
+ALTER TABLE `'.PREFIX_TABLE.'history_summary`
+  ADD COLUMN `history_id_from` int(10) unsigned default NULL,
+  ADD COLUMN `history_id_to` int(10) unsigned default NULL
+;');
+
+$query = '
+SELECT
+    *
+  FROM '.PREFIX_TABLE.'history
+  WHERE summarized = \'true\'
+  ORDER BY id DESC
+  LIMIT 1
+;';
+// note : much faster than searching MAX(ID), ie on my big sample 14 seconds Vs 2 seconds
+$history_lines = query2array($query);
+if (count($history_lines) > 0)
+{
+  $last_summarized = $history_lines[0];
+
+  list($year, $month, $day) = explode('-', $last_summarized['date']);
+  list($hour) = explode(':', $last_summarized['time']);
+
+  single_update(
+    PREFIX_TABLE.'history_summary',
+    array(
+      'history_id_to' => $last_summarized['id'],
+      ),
+    array(
+      'year' => $year,
+      'month' => $month,
+      'day' => $day,
+      'hour' => $hour,
+      )
+    );
+
+  // in case this script would update no summary line, it would mean the
+  // summary has been purged and will be rebuild from scratch, based on the
+  // content of history table
+}
+
+// for now, we keep column history.summarized even if Piwigo 2.9 no longer
+// uses it. We will remove it in a future version. First we need to have
+// "less" lines in history table. This will be possible with the automatic
+// purge implemented in Piwigo 2.9.
+
+echo "\n".$upgrade_description."\n";
+
+?>
diff --git a/install/piwigo_structure-mysql.sql b/install/piwigo_structure-mysql.sql
index 76e9fe90b..c7b33b9f7 100644
--- a/install/piwigo_structure-mysql.sql
+++ b/install/piwigo_structure-mysql.sql
@@ -129,12 +129,10 @@ CREATE TABLE `piwigo_history` (
   `category_id` smallint(5) default NULL,
   `tag_ids` varchar(50) default NULL,
   `image_id` mediumint(8) default NULL,
-  `summarized` enum('true','false') default 'false',
   `image_type` enum('picture','high','other') default NULL,
   `format_id` int(11) unsigned default NULL,
   `auth_key_id` int(11) unsigned DEFAULT NULL,
-  PRIMARY KEY  (`id`),
-  KEY `history_i1` (`summarized`)
+  PRIMARY KEY  (`id`)
 ) ENGINE=MyISAM;
 
 --
@@ -148,6 +146,8 @@ CREATE TABLE `piwigo_history_summary` (
   `day` tinyint(2) default NULL,
   `hour` tinyint(2) default NULL,
   `nb_pages` int(11) default NULL,
+  `history_id_from` int(10) unsigned default NULL,
+  `history_id_to` int(10) unsigned default NULL,
   UNIQUE KEY history_summary_ymdh (`year`,`month`,`day`,`hour`)
 ) ENGINE=MyISAM;