From e286dab47fa30f4005ecae64130a7ef1f06aa3e7 Mon Sep 17 00:00:00 2001
From: zeekling <lingzhaohui@zeekling.cn>
Date: Thu, 1 Jun 2023 00:48:38 +0800
Subject: [PATCH] =?UTF-8?q?=E6=9B=B4=E6=96=B0readme?=
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 ninja
 ```
 
+# 性能优化
+
+[性能变慢的因素](./bad/README.md)
+
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+
+本章列举对ClickHouse性能有影响的操作，主要从存储、查询方面来讲。
+
+# 存储相关
+
+## Nullable
+
+使用`Nullable`类型会对性能产生负面影响，在设计数据库的时候要避免使用`Nullable`。
+
+
+