A different way to get ancestors.

getancestors.php

<?php

$sql = "SELECT slug.object_id from slug where slug.slug = ";
$sql .= "'transfer-of-the-head-dress-ceremony-5';";

$sql = "SELECT id from information_object";

$rows = QubitPdo::fetchAll($sql);
$counter=0;
print(date('Y-m-d H:i:s'));
foreach($rows as $row)
{
  $parentArray = array();
  $parentArray[] = $row->id;
  $start = microtime(true);
  print(json_encode(getAncestors($parentArray)));
  $time_elapsed_secs = microtime(true) - $start;
  print(" " . $time_elapsed_secs . "\n");
  $counter += 1;
}
print($counter."\n");
print(date('Y-m-d H:i:s'));

function getAncestors(&$ancestorArray, $tableName = 'information_object', $root_id = 1, $currentDepth = 0, $maxDepth = 50)
{
  if (end($ancestorArray) == $root_id)
  {
    return $ancestorArray;
  }
  // Use SQL to get parent_id of last element of array 
  $sql = "SELECT t.id, t.parent_id";
  $sql .= " FROM " . $tableName . " t";
  $sql .= ' WHERE t.id=:id;';
  $params = array(':id' => end($ancestorArray));

  $row = QubitPdo::fetchOne($sql, $params);

  // Add it to last element of array
  $ancestorArray[] = $row->parent_id;

  //print("ancestorArray: " . end($ancestorArray)."\n"); 
  //print("t.parent_id: " . t.parent_id . "\n");
  //print("root_id: " . $root_id."\n");
  if ($row->parent_id == $root_id)
  {
    return $ancestorArray;
  }


  // Is currentDepth >= maxDepth?  If so, trigger exception.  Display last 20 elements of array. should never be circular parentage.
  if ($currentDepth >= $maxDepth)
  {
    die("circular looping: ".json_encode($ancestorArray));
  }

  // If not, call self passing array in and currentDepth, and maxDepth
  return getAncestors($ancestorArray, $tableName, $root_id, $currentDepth+1, $maxDepth);
}