function my_post_queries( $query ) {
  // not an admin page and it is the main query
  if (!is_admin() && $query->is_main_query()){
    if(is_home()){
      $query->set('posts_per_page', 1);
      if ( get_option( 'sticky_posts' ) ) {
         $post_ids = merge_sticky_posts(); 
         $query->set('ignore_sticky_posts', 1);
         $query->set('post__in', $post_ids);
         $query->set('orderby', 'post__in');
      }
    }
  }
}
add_action( 'pre_get_posts', 'my_post_queries' );

function merge_sticky_posts() {
  if ( false === ( $post_ids = get_transient( 'all_post_ids' ) ) ) {
  
    $sticky_posts = get_option( 'sticky_posts' );
  
    $args = array(
       'posts_per_page' => -1,
       'ignore_sticky_posts' => 1,
       'post_status'   => 'publish',
       'no_found_rows' => true,
    );
     
    $posts = get_posts($args);
    if($posts) {
      $post_ids = array();
      foreach ($posts as $post) {
        $post_ids[] = $post->ID;
      }
    }
    
    $post_ids = array_merge($sticky_posts, $post_ids);
    set_transient('all_post_ids', $post_ids);
     
  }
  
  return $post_ids;
}


// altered version of the sort-query-by-post-in plugin
// http://wordpress.org/extend/plugins/sort-query-by-post-in/
add_filter( 'posts_orderby', 'merged_post_orderby', 10, 2 );
function merged_post_orderby( $sortby, $thequery ) {

if ( !empty($thequery->query_vars['post__in']) && isset($thequery->query_vars['orderby']) && $thequery->query_vars['orderby'] == 'post__in' ) { 
    $sortby = "find_in_set(ID, '" . implode( ',', $thequery->query_vars['post__in'] ) . "')";
}
    
  return $sortby;
}

// delete transient when updating a post
add_action( 'save_post', 'update_all_ids' );
add_action( 'delete_post', 'update_all_ids' );

function update_all_ids( $post_id ) {
  //verify post is not a revision
  if ( !wp_is_post_revision( $post_id ) ) {
    delete_transient( 'all_post_ids' );
  }
  
}