# N1QL 5.5 进阶教程

N1QL于2015年首次在纽约发布。现在，Couchbase 5.5 已经发布, Couchbase 5.5包含重要的N1QL语言、安全性和性能特性。

ANSI连接(joins)的改进不仅使N1QL加入到SQL标准连接(joins)中，而且还扩展了连接表达式来包含数组。

索引分区提高了索引容量、可用性和性能。

Couchbase 5.5通过数量级改善分组（grouping）和聚合（aggregate）性能。


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://couchbase.shujuwajue.com/n1ql.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.