MDL-59116 analytics: Multiple predictions for each analysable time range

Now we only predict using the most recent range available, this means
that if someone upgrades to moodle 3.4 at three quarters of a course
we will only calculate the latest range, previous ranges were not
displayed anyway once more recent predictions were available.

This commit deletes all previous predictions :) this shouldn't be a
problem in master as we don't provide any guarantee, the alternative
(retrive sampleids from mdl_files) would have been slow and a waste of
time as well as require horrible code in an upgrade step (text fields
do not accept defaults nor we can use NOTNULL).

analytics/classes/local/analyser/base.php

@@ -376,8 +376,8 @@ abstract class base {
             // All ranges are used when we are calculating data for training.
             $ranges = $timesplitting->get_all_ranges();
         } else {
-            // Only some ranges can be used for prediction (it depends on the time range where we are right now).
+            // The latest range that has not yet been used for prediction (it depends on the time range where we are right now).
-            $ranges = $this->get_prediction_ranges($timesplitting);
+            $ranges = $this->get_most_recent_prediction_range($timesplitting);
         }
 
         // There is no need to keep track of the evaluated samples and ranges as we always evaluate the whole dataset.
@@ -385,12 +385,12 @@ abstract class base {
 
             if (empty($ranges)) {
                 $result->status = \core_analytics\model::ANALYSABLE_REJECTED_TIME_SPLITTING_METHOD;
-                $result->message = get_string('nonewdata', 'analytics');
+                $result->message = get_string('noranges', 'analytics');
                 return $result;
             }
 
-            // We skip all samples that are already part of a training dataset, even if they have noe been used for training yet.
+            // We skip all samples that are already part of a training dataset, even if they have not been used for prediction.
-            $sampleids = $this->filter_out_train_samples($sampleids, $timesplitting);
+            $this->filter_out_train_samples($sampleids, $timesplitting);
 
             if (count($sampleids) === 0) {
                 $result->status = \core_analytics\model::ANALYSABLE_REJECTED_TIME_SPLITTING_METHOD;
@@ -400,13 +400,19 @@ abstract class base {
 
             // Only when processing data for predictions.
             if ($target === false) {
-                // We also filter out ranges that have already been used for predictions.
+                // We also filter out samples and ranges that have already been used for predictions.
-                $ranges = $this->filter_out_prediction_ranges($ranges, $timesplitting);
+                $this->filter_out_prediction_samples_and_ranges($sampleids, $ranges, $timesplitting);
+            }
+
+            if (count($sampleids) === 0) {
+                $result->status = \core_analytics\model::ANALYSABLE_REJECTED_TIME_SPLITTING_METHOD;
+                $result->message = get_string('nonewdata', 'analytics');
+                return $result;
             }
 
             if (count($ranges) === 0) {
                 $result->status = \core_analytics\model::ANALYSABLE_REJECTED_TIME_SPLITTING_METHOD;
-                $result->message = get_string('nonewtimeranges', 'analytics');
+                $result->message = get_string('nonewranges', 'analytics');
                 return $result;
             }
         }
@@ -469,7 +475,7 @@ abstract class base {
             if ($target) {
                 $this->save_train_samples($sampleids, $timesplitting, $file);
             } else {
-                $this->save_prediction_ranges($ranges, $timesplitting);
+                $this->save_prediction_samples($sampleids, $ranges, $timesplitting);
             }
         }
 
@@ -480,25 +486,28 @@ abstract class base {
     }
 
     /**
-     * Returns the ranges of a time splitting that can be used to predict.
+     * Returns the most recent range that can be used to predict.
      *
      * @param \core_analytics\local\time_splitting\base $timesplitting
      * @return array
      */
-    protected function get_prediction_ranges($timesplitting) {
+    protected function get_most_recent_prediction_range($timesplitting) {
 
         $now = time();
+        $ranges = $timesplitting->get_all_ranges();
+
+        // Opposite order as we are interested in the last range that can be used for prediction.
+        arsort($ranges);
 
         // We already provided the analysable to the time splitting method, there is no need to feed it back.
-        $predictionranges = array();
+        foreach ($ranges as $rangeindex => $range) {
-        foreach ($timesplitting->get_all_ranges() as $rangeindex => $range) {
             if ($timesplitting->ready_to_predict($range)) {
                 // We need to maintain the same indexes.
-                $predictionranges[$rangeindex] = $range;
+                return array($rangeindex => $range);
             }
         }
 
-        return $predictionranges;
+        return array();
     }
 
     /**
@@ -506,9 +515,8 @@ abstract class base {
      *
      * @param int[] $sampleids
      * @param \core_analytics\local\time_splitting\base $timesplitting
-     * @return int[]
      */
-    protected function filter_out_train_samples($sampleids, $timesplitting) {
+    protected function filter_out_train_samples(&$sampleids, $timesplitting) {
         global $DB;
 
         $params = array('modelid' => $this->modelid, 'analysableid' => $timesplitting->get_analysable()->get_id(),
@@ -526,32 +534,43 @@ abstract class base {
                 $sampleids = array_diff_key($sampleids, $usedsamples);
             }
         }
-
-        return $sampleids;
     }
 
     /**
      * Filters out samples that have already been used for prediction.
      *
+     * @param int[] $sampleids
      * @param array $ranges
      * @param \core_analytics\local\time_splitting\base $timesplitting
-     * @return int[]
      */
-    protected function filter_out_prediction_ranges($ranges, $timesplitting) {
+    protected function filter_out_prediction_samples_and_ranges(&$sampleids, &$ranges, $timesplitting) {
         global $DB;
 
+        if (count($ranges) > 1) {
+            throw new \coding_exception('$ranges argument should only contain one range');
+        }
+
+        $rangeindex = key($ranges);
+
         $params = array('modelid' => $this->modelid, 'analysableid' => $timesplitting->get_analysable()->get_id(),
-            'timesplitting' => $timesplitting->get_id());
+            'timesplitting' => $timesplitting->get_id(), 'rangeindex' => $rangeindex);
+        $predictedrange = $DB->get_record('analytics_predict_samples', $params);
 
-        $predictedranges = $DB->get_records('analytics_predict_ranges', $params);
+        if (!$predictedrange) {
-        foreach ($predictedranges as $predictedrange) {
+            // Nothing to filter out.
-            if (!empty($ranges[$predictedrange->rangeindex])) {
+            return;
-                unset($ranges[$predictedrange->rangeindex]);
-            }
         }
 
-        return $ranges;
+        $predictedrange->sampleids = json_decode($predictedrange->sampleids, true);
+        $missingsamples = array_diff_key($sampleids, $predictedrange->sampleids);
+        if (count($missingsamples) === 0) {
+            // All samples already calculated.
+            unset($ranges[$rangeindex]);
+            return;
+        }
 
+        // Replace the list of samples by the one excluding samples that already got predictions at this range.
+        $sampleids = $missingsamples;
     }
 
     /**
@@ -560,7 +579,7 @@ abstract class base {
      * @param int[] $sampleids
      * @param \core_analytics\local\time_splitting\base $timesplitting
      * @param \stored_file $file
-     * @return bool
+     * @return void
      */
     protected function save_train_samples($sampleids, $timesplitting, $file) {
         global $DB;
@@ -574,28 +593,40 @@ abstract class base {
         $trainingsamples->sampleids = json_encode($sampleids);
         $trainingsamples->timecreated = time();
 
-        return $DB->insert_record('analytics_train_samples', $trainingsamples);
+        $DB->insert_record('analytics_train_samples', $trainingsamples);
     }
 
     /**
      * Saves samples that have just been used for prediction.
      *
+     * @param int[] $sampleids
      * @param array $ranges
      * @param \core_analytics\local\time_splitting\base $timesplitting
      * @return void
      */
-    protected function save_prediction_ranges($ranges, $timesplitting) {
+    protected function save_prediction_samples($sampleids, $ranges, $timesplitting) {
         global $DB;
 
-        $predictionrange = new \stdClass();
+        if (count($ranges) > 1) {
-        $predictionrange->modelid = $this->modelid;
+            throw new \coding_exception('$ranges argument should only contain one range');
-        $predictionrange->analysableid = $timesplitting->get_analysable()->get_id();
+        }
-        $predictionrange->timesplitting = $timesplitting->get_id();
-        $predictionrange->timecreated = time();
 
-        foreach ($ranges as $rangeindex => $unused) {
+        $rangeindex = key($ranges);
-            $predictionrange->rangeindex = $rangeindex;
+
-            $DB->insert_record('analytics_predict_ranges', $predictionrange);
+        $params = array('modelid' => $this->modelid, 'analysableid' => $timesplitting->get_analysable()->get_id(),
+            'timesplitting' => $timesplitting->get_id(), 'rangeindex' => $rangeindex);
+        if ($predictionrange = $DB->get_record('analytics_predict_samples', $params)) {
+            // Append the new samples used for prediction.
+            $prevsamples = json_decode($predictionrange->sampleids, true);
+            $predictionrange->sampleids = json_encode($prevsamples + $sampleids);
+            $predictionrange->timemodified = time();
+            $DB->update_record('analytics_predict_samples', $predictionrange);
+        } else {
+            $predictionrange = (object)$params;
+            $predictionrange->sampleids = json_encode($sampleids);
+            $predictionrange->timecreated = time();
+            $predictionrange->timemodified = $predictionrange->timecreated;
+            $DB->insert_record('analytics_predict_samples', $predictionrange);
         }
     }
 }

analytics/classes/model.php

@@ -1013,7 +1013,7 @@ class model {
      */
     public function any_prediction_obtained() {
         global $DB;
-        return $DB->record_exists('analytics_predict_ranges',
+        return $DB->record_exists('analytics_predict_samples',
             array('modelid' => $this->model->id, 'timesplitting' => $this->model->timesplitting));
     }
 
@@ -1317,8 +1317,8 @@ class model {
     private function clear_model() {
         global $DB;
 
-        $DB->delete_records('analytics_predict_ranges', array('modelid' => $this->model->id));
         $DB->delete_records('analytics_predictions', array('modelid' => $this->model->id));
+        $DB->delete_records('analytics_predict_samples', array('modelid' => $this->model->id));
         $DB->delete_records('analytics_train_samples', array('modelid' => $this->model->id));
         $DB->delete_records('analytics_used_files', array('modelid' => $this->model->id));
 

analytics/tests/prediction_test.php

@@ -31,6 +31,8 @@ require_once(__DIR__ . '/fixtures/test_indicator_random.php');
 require_once(__DIR__ . '/fixtures/test_target_shortname.php');
 require_once(__DIR__ . '/fixtures/test_static_target_shortname.php');
 
+require_once(__DIR__ . '/../../course/lib.php');
+
 /**
  * Unit tests for evaluation, training and prediction.
  *
@@ -81,7 +83,7 @@ class core_analytics_prediction_testcase extends advanced_testcase {
         }
 
         // 1 range for each analysable.
-        $predictedranges = $DB->get_records('analytics_predict_ranges', array('modelid' => $model->get_id()));
+        $predictedranges = $DB->get_records('analytics_predict_samples', array('modelid' => $model->get_id()));
         $this->assertCount(2, $predictedranges);
         $this->assertEquals(1, $DB->count_records('analytics_used_files',
             array('modelid' => $model->get_id(), 'action' => 'predicted')));
@@ -91,7 +93,7 @@ class core_analytics_prediction_testcase extends advanced_testcase {
 
         // No new generated files nor records as there are no new courses available.
         $model->predict();
-        $predictedranges = $DB->get_records('analytics_predict_ranges', array('modelid' => $model->get_id()));
+        $predictedranges = $DB->get_records('analytics_predict_samples', array('modelid' => $model->get_id()));
         $this->assertCount(2, $predictedranges);
         $this->assertEquals(1, $DB->count_records('analytics_used_files',
             array('modelid' => $model->get_id(), 'action' => 'predicted')));
@@ -104,11 +106,11 @@ class core_analytics_prediction_testcase extends advanced_testcase {
      *
      * @dataProvider provider_ml_training_and_prediction
      * @param string $timesplittingid
-     * @param int $npredictedranges
+     * @param int $predictedrangeindex
      * @param string $predictionsprocessorclass
      * @return void
      */
-    public function test_ml_training_and_prediction($timesplittingid, $npredictedranges, $predictionsprocessorclass) {
+    public function test_ml_training_and_prediction($timesplittingid, $predictedrangeindex, $predictionsprocessorclass) {
         global $DB;
 
         $this->resetAfterTest(true);
@@ -176,22 +178,75 @@ class core_analytics_prediction_testcase extends advanced_testcase {
             $this->assertEquals($correct[$sampleid], $predictiondata->prediction);
         }
 
-        // 2 ranges will be predicted.
+        // 1 range will be predicted.
-        $predictedranges = $DB->get_records('analytics_predict_ranges', array('modelid' => $model->get_id()));
+        $predictedranges = $DB->get_records('analytics_predict_samples', array('modelid' => $model->get_id()));
-        $this->assertCount($npredictedranges, $predictedranges);
+        $this->assertCount(1, $predictedranges);
+        foreach ($predictedranges as $predictedrange) {
+            $this->assertEquals($predictedrangeindex, $predictedrange->rangeindex);
+            $sampleids = json_decode($predictedrange->sampleids, true);
+            $this->assertCount(2, $sampleids);
+            $this->assertContains($course1->id, $sampleids);
+            $this->assertContains($course2->id, $sampleids);
+        }
         $this->assertEquals(1, $DB->count_records('analytics_used_files',
             array('modelid' => $model->get_id(), 'action' => 'predicted')));
-        // 2 predictions for each range.
+        // 2 predictions.
-        $this->assertEquals(2 * $npredictedranges, $DB->count_records('analytics_predictions',
+        $this->assertEquals(2, $DB->count_records('analytics_predictions',
             array('modelid' => $model->get_id())));
 
         // No new generated files nor records as there are no new courses available.
         $model->predict();
-        $predictedranges = $DB->get_records('analytics_predict_ranges', array('modelid' => $model->get_id()));
+        $predictedranges = $DB->get_records('analytics_predict_samples', array('modelid' => $model->get_id()));
-        $this->assertCount($npredictedranges, $predictedranges);
+        $this->assertCount(1, $predictedranges);
+        foreach ($predictedranges as $predictedrange) {
+            $this->assertEquals($predictedrangeindex, $predictedrange->rangeindex);
+        }
         $this->assertEquals(1, $DB->count_records('analytics_used_files',
             array('modelid' => $model->get_id(), 'action' => 'predicted')));
-        $this->assertEquals(2 * $npredictedranges, $DB->count_records('analytics_predictions',
+        $this->assertEquals(2, $DB->count_records('analytics_predictions',
+            array('modelid' => $model->get_id())));
+
+        // New samples that can be used for prediction.
+        $courseparams = $params + array('shortname' => 'cccccc', 'fullname' => 'cccccc', 'visible' => 0);
+        $course3 = $this->getDataGenerator()->create_course($courseparams);
+        $courseparams = $params + array('shortname' => 'dddddd', 'fullname' => 'dddddd', 'visible' => 0);
+        $course4 = $this->getDataGenerator()->create_course($courseparams);
+
+        $result = $model->predict();
+
+        $predictedranges = $DB->get_records('analytics_predict_samples', array('modelid' => $model->get_id()));
+        $this->assertCount(1, $predictedranges);
+        foreach ($predictedranges as $predictedrange) {
+            $this->assertEquals($predictedrangeindex, $predictedrange->rangeindex);
+            $sampleids = json_decode($predictedrange->sampleids, true);
+            $this->assertCount(4, $sampleids);
+            $this->assertContains($course1->id, $sampleids);
+            $this->assertContains($course2->id, $sampleids);
+            $this->assertContains($course3->id, $sampleids);
+            $this->assertContains($course4->id, $sampleids);
+        }
+        $this->assertEquals(2, $DB->count_records('analytics_used_files',
+            array('modelid' => $model->get_id(), 'action' => 'predicted')));
+        $this->assertEquals(4, $DB->count_records('analytics_predictions',
+            array('modelid' => $model->get_id())));
+
+        // New visible course (for training).
+        $course5 = $this->getDataGenerator()->create_course(array('shortname' => 'aaa', 'fullname' => 'aa'));
+        $course6 = $this->getDataGenerator()->create_course();
+        $result = $model->train();
+        $this->assertEquals(2, $DB->count_records('analytics_used_files',
+            array('modelid' => $model->get_id(), 'action' => 'trained')));
+
+        // Update one of the courses to not visible, it should be used again for prediction.
+        $course5->visible = 0;
+        update_course($course5);
+
+        $model->predict();
+        $this->assertEquals(1, $DB->count_records('analytics_predict_samples',
+            array('modelid' => $model->get_id())));
+        $this->assertEquals(2, $DB->count_records('analytics_used_files',
+            array('modelid' => $model->get_id(), 'action' => 'predicted')));
+        $this->assertEquals(4, $DB->count_records('analytics_predictions',
             array('modelid' => $model->get_id())));
 
         set_config('enabled_stores', '', 'tool_log');
@@ -205,8 +260,8 @@ class core_analytics_prediction_testcase extends advanced_testcase {
      */
     public function provider_ml_training_and_prediction() {
         $cases = array(
-            'no_splitting' => array('\core\analytics\time_splitting\no_splitting', 1),
+            'no_splitting' => array('\core\analytics\time_splitting\no_splitting', 0),
-            'quarters' => array('\core\analytics\time_splitting\quarters', 4)
+            'quarters' => array('\core\analytics\time_splitting\quarters', 3)
         );
 
         // We need to test all system prediction processors.

lang/en/analytics.php

@@ -60,15 +60,17 @@ $string['insightinfomessagehtml'] = 'The system generated some insights for you:
 $string['invalidtimesplitting'] = 'Model with id {$a} needs a time splitting method before it can be used to train';
 $string['invalidanalysablefortimesplitting'] = 'It can not be analysed using {$a} time splitting method';
 $string['nocourses'] = 'No courses to analyse';
-$string['nodata'] = 'No data available';
 $string['modeloutputdir'] = 'Models output directory';
 $string['modeloutputdirinfo'] = 'Directory where prediction processors store all evaluation info. Useful for debugging and research.';
 $string['noevaluationbasedassumptions'] = 'Models based on assumptions can not be evaluated';
+$string['nodata'] = 'No data to analyse';
 $string['noinsightsmodel'] = 'This model does not generate insights';
 $string['noinsights'] = 'No insights reported';
 $string['nonewdata'] = 'No new data available';
+$string['nonewranges'] = 'No new predictions yet';
 $string['nonewtimeranges'] = 'No new time ranges, nothing to predict';
 $string['nopredictionsyet'] = 'No predictions available yet';
+$string['noranges'] = 'No predictions yet';
 $string['notrainingbasedassumptions'] = 'Models based on assumptions do not need training';
 $string['novaliddata'] = 'No valid data available';
 $string['novalidsamples'] = 'No valid samples available';

lib/db/install.xml

@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="UTF-8" ?>
-<XMLDB PATH="lib/db" VERSION="20170502" COMMENT="XMLDB file for core Moodle tables"
+<XMLDB PATH="lib/db" VERSION="20170721" COMMENT="XMLDB file for core Moodle tables"
     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
     xsi:noNamespaceSchemaLocation="../../lib/xmldb/xmldb.xsd"
 >
@@ -3592,7 +3592,7 @@
         <FIELD NAME="target" TYPE="char" LENGTH="255" NOTNULL="true" SEQUENCE="false"/>
         <FIELD NAME="indicators" TYPE="text" NOTNULL="true" SEQUENCE="false"/>
         <FIELD NAME="timesplitting" TYPE="char" LENGTH="255" NOTNULL="false" SEQUENCE="false"/>
-        <FIELD NAME="score" TYPE="number" LENGTH="10" DECIMALS="5" NOTNULL="true" DEFAULT="0" SEQUENCE="false"/>
+        <FIELD NAME="score" TYPE="number" LENGTH="10" NOTNULL="true" DEFAULT="0" SEQUENCE="false" DECIMALS="5"/>
         <FIELD NAME="info" TYPE="text" NOTNULL="false" SEQUENCE="false"/>
         <FIELD NAME="dir" TYPE="text" NOTNULL="true" SEQUENCE="false"/>
         <FIELD NAME="timecreated" TYPE="int" LENGTH="10" NOTNULL="true" SEQUENCE="false"/>
@@ -3605,7 +3605,6 @@
         <INDEX NAME="modelid" UNIQUE="false" FIELDS="modelid" COMMENT="Index on modelid"/>
       </INDEXES>
     </TABLE>
-
     <TABLE NAME="analytics_predictions" COMMENT="Predictions">
       <FIELDS>
         <FIELD NAME="id" TYPE="int" LENGTH="10" NOTNULL="true" SEQUENCE="true"/>
@@ -3614,7 +3613,7 @@
         <FIELD NAME="sampleid" TYPE="int" LENGTH="10" NOTNULL="true" SEQUENCE="false"/>
         <FIELD NAME="rangeindex" TYPE="int" LENGTH="5" NOTNULL="true" SEQUENCE="false"/>
         <FIELD NAME="prediction" TYPE="int" LENGTH="2" NOTNULL="true" SEQUENCE="false"/>
-        <FIELD NAME="predictionscore" TYPE="number" LENGTH="10" DECIMALS="5" NOTNULL="true" SEQUENCE="false"/>
+        <FIELD NAME="predictionscore" TYPE="number" LENGTH="10" NOTNULL="true" SEQUENCE="false" DECIMALS="5"/>
         <FIELD NAME="calculations" TYPE="text" NOTNULL="true" SEQUENCE="false"/>
         <FIELD NAME="timecreated" TYPE="int" LENGTH="10" NOTNULL="true" DEFAULT="0" SEQUENCE="false"/>
       </FIELDS>
@@ -3642,20 +3641,22 @@
         <INDEX NAME="modelidandanalysableidandtimesplitting" UNIQUE="false" FIELDS="modelid, analysableid, timesplitting" COMMENT="Index on modelid and analysableid and timesplitting"/>
       </INDEXES>
     </TABLE>
-    <TABLE NAME="analytics_predict_ranges" COMMENT="Time ranges already used for predictions.">
+    <TABLE NAME="analytics_predict_samples" COMMENT="Samples already used for predictions.">
       <FIELDS>
         <FIELD NAME="id" TYPE="int" LENGTH="10" NOTNULL="true" SEQUENCE="true"/>
         <FIELD NAME="modelid" TYPE="int" LENGTH="10" NOTNULL="true" SEQUENCE="false"/>
         <FIELD NAME="analysableid" TYPE="int" LENGTH="10" NOTNULL="true" SEQUENCE="false"/>
         <FIELD NAME="timesplitting" TYPE="char" LENGTH="255" NOTNULL="true" SEQUENCE="false"/>
         <FIELD NAME="rangeindex" TYPE="int" LENGTH="10" NOTNULL="true" SEQUENCE="false"/>
+        <FIELD NAME="sampleids" TYPE="text" NOTNULL="true" SEQUENCE="false"/>
         <FIELD NAME="timecreated" TYPE="int" LENGTH="10" NOTNULL="true" DEFAULT="0" SEQUENCE="false"/>
+        <FIELD NAME="timemodified" TYPE="int" LENGTH="10" NOTNULL="true" DEFAULT="0" SEQUENCE="false"/>
       </FIELDS>
       <KEYS>
         <KEY NAME="primary" TYPE="primary" FIELDS="id"/>
       </KEYS>
       <INDEXES>
-        <INDEX NAME="modelidandanalysableidandtimesplitting" UNIQUE="false" FIELDS="modelid, analysableid, timesplitting" COMMENT="Index on modelid and analysableid and timesplitting"/>
+        <INDEX NAME="modelidandanalysableidandtimesplittingandrangeindex" UNIQUE="false" FIELDS="modelid, analysableid, timesplitting, rangeindex" COMMENT="Index on modelid and analysableid and timesplitting"/>
       </INDEXES>
     </TABLE>
     <TABLE NAME="analytics_used_files" COMMENT="Files that have already been used for training and prediction.">

lib/db/upgrade.php

@@ -2255,5 +2255,40 @@ function xmldb_main_upgrade($oldversion) {
         upgrade_main_savepoint(true, 2017072700.02);
     }
 
+    if ($oldversion < 2017080400.01) {
+
+        // Get the table by its previous name.
+        $table = new xmldb_table('analytics_predict_ranges');
+        if ($dbman->table_exists($table)) {
+
+            // We can only accept this because we are in master.
+            $DB->delete_records('analytics_predictions');
+            $DB->delete_records('analytics_used_files', array('action' => 'predicted'));
+            $DB->delete_records('analytics_predict_ranges');
+
+            // Define field sampleids to be added to analytics_predict_ranges (renamed below to analytics_predict_samples).
+            $field = new xmldb_field('sampleids', XMLDB_TYPE_TEXT, null, null, XMLDB_NOTNULL, null, null, 'rangeindex');
+
+            // Conditionally launch add field sampleids.
+            if (!$dbman->field_exists($table, $field)) {
+                $dbman->add_field($table, $field);
+            }
+
+            // Define field timemodified to be added to analytics_predict_ranges (renamed below to analytics_predict_samples).
+            $field = new xmldb_field('timemodified', XMLDB_TYPE_INTEGER, '10', null, XMLDB_NOTNULL, null, '0', 'timecreated');
+
+            // Conditionally launch add field timemodified.
+            if (!$dbman->field_exists($table, $field)) {
+                $dbman->add_field($table, $field);
+            }
+
+            // Rename the table to its new name.
+            $dbman->rename_table($table, 'analytics_predict_samples');
+        }
+
+        // Main savepoint reached.
+        upgrade_main_savepoint(true, 2017080400.01);
+    }
+
     return true;
 }

version.php

@@ -29,7 +29,7 @@
 
 defined('MOODLE_INTERNAL') || die();
 
-$version  = 2017080400.00;              // YYYYMMDD      = weekly release date of this DEV branch.
+$version  = 2017080400.01;              // YYYYMMDD      = weekly release date of this DEV branch.
                                         //         RR    = release increments - 00 in DEV branches.
                                         //           .XX = incremental changes.