From a4bafeaa94541641c36f3c0e989b1af0828bbc51 Mon Sep 17 00:00:00 2001
From: Nathan ter Bogt <nterbogt@gmail.com>
Date: Wed, 3 May 2023 21:44:09 +1000
Subject: [PATCH] Optimise the use case where the two conditions overlap in an
 =

---
 src/Storage/DbalNestedSet.php | 18 ++++++++++++------
 1 file changed, 12 insertions(+), 6 deletions(-)

diff --git a/src/Storage/DbalNestedSet.php b/src/Storage/DbalNestedSet.php
index f5519184..0fb396eb 100644
--- a/src/Storage/DbalNestedSet.php
+++ b/src/Storage/DbalNestedSet.php
@@ -142,13 +142,19 @@ public function findDescendants(NodeKey $nodeKey, int $depth = 0, int $start = 1
       ->orderBy('child.left_pos', 'ASC')
       ->setParameter('id', $nodeKey->getId())
       ->setParameter('revision_id', $nodeKey->getRevisionId());
-    if ($start > 0) {
-      $query->andWhere('child.depth >= :start_depth + parent.depth')
-        ->setParameter('start_depth', $start);
+    if ($depth > 0 && $depth == $start) {
+      $query->andWhere('child.depth = :depth + parent.depth')
+        ->setParameter('depth', $depth);
     }
-    if ($depth > 0) {
-      $query->andWhere('child.depth <= :depth + parent.depth')
-        ->setParameter('depth', $start + $depth - 1);
+    else {
+      if ($start > 0) {
+        $query->andWhere('child.depth >= :start_depth + parent.depth')
+          ->setParameter('start_depth', $start);
+      }
+      if ($depth > 0) {
+        $query->andWhere('child.depth <= :depth + parent.depth')
+          ->setParameter('depth', $start + $depth - 1);
+      }
     }
     $stmt = $query->executeQuery();
     assert($stmt instanceof Result);