SQL : performances

Tentative de reformulation de la requête principale pour améliorer les
performances.
Utilisation d'une sous-jointure qui retourne uniquement e.id.
Sur mon serveur avec 13000 articles, la requête de la page d'accueil
sans article non lu mettait 1.38s avant le patch, contre 0.08s après (en
désactivant bien sûr le cache SQL).

Il faudra re-tester et tenter d'autres optimisations (notamment sur les
index) avec un nombre d'articles plus important.

Avant :
SELECT SQL_NO_CACHE e.id, e.guid, e.title, e.author,
UNCOMPRESS(e.content_bin) AS content, e.link, e.date, e.is_read,
e.is_favorite, e.id_feed, e.tags FROM `freshrss_alex_entry` e INNER JOIN
`freshrss_alex_feed` f ON e.id_feed = f.id WHERE f.priority > 0 AND
(e.id >= 1371597014000000 OR e.is_favorite = 1 OR f.keep_history = 1)
ORDER BY e.id DESC LIMIT 33;

Après :
SELECT SQL_NO_CACHE e.id, e.guid, e.title, e.author,
UNCOMPRESS(e.content_bin) AS content, e.link, e.date, e.is_read,
e.is_favorite, e.id_feed, e.tags FROM `freshrss_alex_entry` e INNER JOIN
(SELECT e1.id FROM `freshrss_alex_entry` e1 INNER JOIN
`freshrss_alex_feed` f ON e1.id_feed = f.id WHERE f.priority > 0 AND
(e1.id >= 1371597014000000 OR e1.is_favorite = 1 OR f.keep_history = 1)
ORDER BY e1.id DESC LIMIT 33) e2 ON e2.id = e.id ORDER BY e.id DESC;

app/Controllers/indexController.php

@@ -124,9 +124,11 @@ class FreshRSS_index_Controller extends Minz_ActionController {
 			}
 		}
 
+		$today = @strtotime('today');
+
 		// on calcule la date des articles les plus anciens qu'on affiche
 		$nb_month_old = $this->view->conf->oldEntries ();
-		$date_min = time () - (3600 * 24 * 30 * $nb_month_old);
+		$date_min = $today - (3600 * 24 * 30 * $nb_month_old);	//Do not use a fast changing value such as time() to allow SQL caching
 
 		try {
 			$entries = $this->entryDAO->listWhere($getType, $getId, $state, $order, $nb + 1, $first, $filter, $date_min);

app/Models/EntryDAO.php

@@ -269,7 +269,7 @@ class FreshRSS_EntryDAO extends Minz_ModelPdo {
 				$joinFeed = true;
 				break;
 			case 's':
-				$where .= 'e.is_favorite = 1 ';
+				$where .= 'e1.is_favorite = 1 ';
 				break;
 			case 'c':
 				$where .= 'f.category = ? ';
@@ -277,7 +277,7 @@ class FreshRSS_EntryDAO extends Minz_ModelPdo {
 				$joinFeed = true;
 				break;
 			case 'f':
-				$where .= 'e.id_feed = ? ';
+				$where .= 'e1.id_feed = ? ';
 				$values[] = intval($id);
 				break;
 			default:
@@ -287,10 +287,10 @@ class FreshRSS_EntryDAO extends Minz_ModelPdo {
 			case 'all':
 				break;
 			case 'not_read':
-				$where .= 'AND e.is_read = 0 ';
+				$where .= 'AND e1.is_read = 0 ';
 				break;
 			case 'read':
-				$where .= 'AND e.is_read = 1 ';
+				$where .= 'AND e1.is_read = 1 ';
 				break;
 			default:
 				throw new FreshRSS_EntriesGetter_Exception ('Bad state in Entry->listByType: [' . $state . ']!');
@@ -303,10 +303,10 @@ class FreshRSS_EntryDAO extends Minz_ModelPdo {
 				throw new FreshRSS_EntriesGetter_Exception ('Bad order in Entry->listByType: [' . $order . ']!');
 		}
 		if ($firstId !== '') {
-			$where .= 'AND e.id ' . ($order === 'DESC' ? '<=' : '>=') . $firstId . ' ';
+			$where .= 'AND e1.id ' . ($order === 'DESC' ? '<=' : '>=') . $firstId . ' ';
 		}
 		if (($date_min > 0) && ($type !== 's')) {
-			$where .= 'AND (e.id >= ' . $date_min . '000000 OR e.is_favorite = 1 OR f.keep_history = 1) ';
+			$where .= 'AND (e1.id >= ' . $date_min . '000000 OR e1.is_favorite = 1 OR f.keep_history = 1) ';
 			$joinFeed = true;
 		}
 		$terms = array_unique(explode(' ', trim($filter)));
@@ -315,10 +315,10 @@ class FreshRSS_EntryDAO extends Minz_ModelPdo {
 		foreach ($terms as $word) {
 			if (!empty($word)) {
 				if ($word[0] === '#' && isset($word[1])) {
-					$having .= 'AND e.tags LIKE ? ';
+					$having .= 'AND e1.tags LIKE ? ';
 					$values[] = '%' . $word .'%';
 				} elseif (!empty($word)) {
-					$having .= 'AND (e.title LIKE ? OR content LIKE ?) ';
+					$having .= 'AND (e1.title LIKE ? OR content LIKE ?) ';
 					$values[] = '%' . $word .'%';
 					$values[] = '%' . $word .'%';
 				}
@@ -327,15 +327,15 @@ class FreshRSS_EntryDAO extends Minz_ModelPdo {
 
 		$sql = 'SELECT e.id, e.guid, e.title, e.author, UNCOMPRESS(e.content_bin) AS content, e.link, e.date, e.is_read, e.is_favorite, e.id_feed, e.tags '
 		     . 'FROM `' . $this->prefix . 'entry` e '
-		     . ($joinFeed ? 'INNER JOIN `' . $this->prefix . 'feed` f ON e.id_feed = f.id ' : '')
-		     . 'WHERE ' . $where
-		     . (empty($having) ? '' : 'HAVING' . substr($having, 3))
+		     . 'INNER JOIN (SELECT e1.id FROM `' . $this->prefix . 'entry` e1 '
+			     . ($joinFeed ? 'INNER JOIN `' . $this->prefix . 'feed` f ON e1.id_feed = f.id ' : '')
+			     . 'WHERE ' . $where
+			     . (empty($having) ? '' : 'HAVING' . substr($having, 3))
+			     . 'ORDER BY e1.id ' . $order
+			     . ($limit > 0 ? ' LIMIT ' . $limit : '')	//TODO: See http://explainextended.com/2009/10/23/mysql-order-by-limit-performance-late-row-lookups/
+		     . ') e2 ON e2.id = e.id '
 		     . 'ORDER BY e.id ' . $order;
 
-		if ($limit > 0) {
-			$sql .= ' LIMIT ' . $limit;	//TODO: See http://explainextended.com/2009/10/23/mysql-order-by-limit-performance-late-row-lookups/
-		}
-
 		$stm = $this->bd->prepare ($sql);
 		$stm->execute ($values);