From 95e8483c8b941b2bd57543397027663b1b46c716 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Johan=20R=C3=B8ed?= <johan@fremby.no>
Date: Wed, 23 Sep 2026 14:56:49 +0200
Subject: [PATCH] docs: tip to read the column list once per render

Cowritten by Claude
---
 docs-app/src/templates/1-get-started/index.gjs.md | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/docs-app/src/templates/1-get-started/index.gjs.md b/docs-app/src/templates/1-get-started/index.gjs.md
index ebccf054..585815a9 100644
--- a/docs-app/src/templates/1-get-started/index.gjs.md
+++ b/docs-app/src/templates/1-get-started/index.gjs.md
@@ -217,6 +217,10 @@ export function localSort(data, sorts) {
 
 </div>
 
+> [!TIP]
+> Read the column list once per render, as the example above does, and pass it down.
+> `columns.for(table)` returns a new array on every call, so reading it once per row costs O(rows × columns) — including in a row component that takes the table and reads the list itself.
+
 ## Installation
 
 Use your favorite package manager / installation tool -- the library is called `@universal-ember/table`.