ClickHouse/docs/zh/engines/database-engines/lazy.md

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---
slug: /zh/engines/database-engines/lazy
sidebar_position: 31
sidebar_label: Lazy
---
# Lazy {#lazy}
在最后一次访问之后只在RAM中保存`expiration_time_in_seconds`秒。只能用于\*Log表。
它是为存储许多小的\*Log表而优化的对于这些表访问之间有很长的时间间隔。
## 创建数据库 {#creating-a-database}
``` sql
CREATE DATABASE testlazy ENGINE = Lazy(expiration_time_in_seconds);
```