Merge v2.5.0

.github/workflows/deploy.yml

@@ -6,7 +6,7 @@ on:
 
 jobs:
   deploy:
-    runs-on: ubuntu-18.04
+    runs-on: ubuntu-20.04
     steps:
       - uses: actions/checkout@v2
         with:
@@ -29,21 +29,16 @@ jobs:
           pip3 install -r ./requirements.txt
 
       - name: Git Config
-        run: git config user.name jerry.liang && git config user.email ${{secrets.GIT_EMAIL}}
+        run: git config user.name whitewum && git config user.email [email protected]
 
       - name: mike list delete
         run: |
-          #mike delete 2.0.0 -p
           mike list
-
-      - name: Mike Deploy
-        run: mike deploy master -p --rebase
-
-#      - name: set-default
-#        run: mike set-default 2.0.1 -p
-
-      - name: mike list
-        run: mike list
+
+      - name: Mike Deploy master
+        run: |
+          mike deploy master -p --rebase
+          mike list
 
       # - name: Deploy
       #   uses: peaceiris/actions-gh-pages@v3

docs-2.0/1.introduction/2.1.path.md

@@ -8,7 +8,7 @@ The following picture is an example for a brief introduction.
 
 ![path](../images/path1.png)
 
-## walk
+## Walk
 
 A `walk` is a finite or infinite sequence of edges. Both vertices and edges can be repeatedly visited in graph traversal.
 
@@ -18,7 +18,7 @@ In the above picture C, D, and E form a cycle. So, this picture contains infinit
 
     `GO` statements use `walk`.
 
-## trail
+## Trail
 
 A `trail` is a finite sequence of edges. Only vertices can be repeatedly visited in graph traversal. The Seven Bridges of Königsberg is a typical `trail`.
 
@@ -40,7 +40,7 @@ There are two special cases of trail, `cycle`, and `circuit`. The following pict
 
    A `circuit` refers to a closed `trail`. Edges cannot be repeatedly visited in graph traversal. Apart from the terminal vertices, other vertices can also be repeatedly visited. The longest path in this picture: `A->B->C->D->E->C->A`.
 
-## path
+## Path
 
 A `path` is a finite sequence of edges. Neither vertices nor edges can be repeatedly visited in graph traversal.
 

docs-2.0/1.introduction/3.nebula-graph-architecture/4.storage-service.md

@@ -14,7 +14,7 @@ The other is the Storage Service that stores the data, which is run by the nebul
 
 - High availability (Raft)
 
-- Supports synchronizing with the third party systems, such as [Elasticsearch](../4.deployment-and-installation/6.deploy-text-based-index/2.deploy-es.md).
+- Supports synchronizing with the third party systems, such as [Elasticsearch](../../4.deployment-and-installation/6.deploy-text-based-index/2.deploy-es.md).
 
 ## The architecture of Storage Service
 

docs-2.0/1.introduction/3.vid.md

@@ -18,7 +18,7 @@ In Nebula Graph, a vertex is uniquely identified by its ID, which is called a VI
 
   + When two `INSERT` statements with the same VID but different tags, like `TAG A` and `TAG B`, are operated at the same time, the operation of `Tag A` will not affect `Tag B`.
 
--  VIDs will usually be indexed and stored into memory（in the way of LSM-tree). Thus, direct access to VIDs enjoys peak performance.
+-  VIDs will usually be indexed and stored into memory (in the way of LSM-tree). Thus, direct access to VIDs enjoys peak performance.
 
 ## VID Operation
 
@@ -47,3 +47,20 @@ VIDs can be generated via applications. Here are some tips:
 ## Define and modify the data type of VIDs
 
 The data type of VIDs must be defined when you [create the graph space](../3.ngql-guide/9.space-statements/1.create-space.md). Once defined, it cannot be modified.
+
+<!--
+## "查询起始点"(`start vid`)与全局扫描
+
+绝大多数情况下，Nebula Graph 的查询语句(`MATCH`, `GO`, `LOOKUP`)的执行计划，必须要通过一定方式找到查询起始点的 VID (`start vid`)。
+
+定位 `start vid` 只有两种方式：
+
+1. 例如 `GO FROM "player100" OVER` 是在语句中显式的指明 `start vid` 是 "player100";
+
+2. 例如, `LOOKUP ON player WHERE player.name == "Tony Parker"` 或者 `MATCH (v:player {name:"Tony Parker"}) `，是通过属性 `player.name` 的索引来定位到 `start vid`；
+
+
+!!! caution 不能在没有 `start vid` 情况下进行全局扫描；
+
+    例如 `match (n) return n;` 会返回错误，因为此时无法定位到 `start vid`；这是一个全局扫描，因此被禁止。
+-->

docs-2.0/14.client/4.nebula-java-client.md

@@ -33,13 +33,13 @@ You have installed Java 8.0 or later versions.
 
 !!! note
 
-    We recommended that each thread use one session. If multiple threads use the same session, the performance will be reduced.
+    We recommend that each thread uses one session. If multiple threads use the same session, the performance will be reduced.
 
 When importing a Maven project with tools such as IDEA, set the following dependency in `pom.xml`.
 
 !!! note
 
-    `2.0.0-SNAPSHOT` indicates the daily development version that may have unknow issues. We recommend that you replace `2.0.0-SNAPSHOT` with a released version number to use a table version.
+    `2.0.0-SNAPSHOT` indicates the daily development version that may have unknown issues. We recommend that you replace `2.0.0-SNAPSHOT` with a released version number to use a table version.
 
 ```bash
 <dependency>

docs-2.0/14.client/5.nebula-python-client.md

@@ -53,7 +53,7 @@ $ pip install nebula2-python==<version>
 
   !!! note
 
-        To run unit tests in the development mode, install `requirements-dev.txt` instead.
+        To run unit tests in the development mode, install dependencies of `requirements-dev.txt`.
 
 4. Run the following command to install Nebula Python.
 
@@ -80,7 +80,7 @@ ok = connection_pool.init([('192.168.xx.1', 9669)], config)
 # Get the session from the connection pool.
 session = connection_pool.get_session('root', 'nebula')
 
-# Selection a graph space.
+# Select a graph space.
 session.execute('USE basketballplayer')
 
 # Run the SHOW TAGS statement.

docs-2.0/15.contribution/how-to-contribute.md

@@ -108,9 +108,9 @@ The Nebula Graph project has many [repositories](https://github.com/vesoft-inc).
   git checkout -b myfeature
   ```
 
-!!! note
+  !!! note
 
-    Because the PR often consists of several commits, which might be squashed while being merged into upstream. We strongly suggest you to open a separate topic branch to make your changes on. After merged, this topic branch can be just abandoned, thus you could synchronize your master branch with upstream easily with a rebase like above. Otherwise, if you commit your changes directly into master, you need to use a hard reset on the master branch. For example:
+        Because the PR often consists of several commits, which might be squashed while being merged into upstream. We strongly suggest you to open a separate topic branch to make your changes on. After merged, this topic branch can be just abandoned, thus you could synchronize your master branch with upstream easily with a rebase like above. Otherwise, if you commit your changes directly into master, you need to use a hard reset on the master branch. For example:
 
         ```bash
         git fetch upstream
@@ -198,7 +198,7 @@ Email address: [email protected]
 
 WeChat: NebulaGraphbot
 
-Slack：[Join Slack](https://join.slack.com/t/nebulagraph/shared_invite/zt-7ybejuqa-NCZBroh~PCh66d9kOQj45g)
+Slack: [Join Slack](https://join.slack.com/t/nebulagraph/shared_invite/zt-7ybejuqa-NCZBroh~PCh66d9kOQj45g)
 
 ### Step 2: Get the information of the project recipient
 

docs-2.0/2.quick-start/1.quick-start-workflow.md

@@ -21,73 +21,3 @@ Users can quickly deploy and use Nebula Graph in the following steps.
 4. [CRUD in Nebula Graph](4.nebula-graph-crud.md)
 
   Users can use nGQL (Nebula Graph Query Language) to run CRUD after connecting to Nebula Graph.
-
-<!--
-# 快速入门
-
-快速入门将介绍如何简单地使用Nebula Graph, 包括部署、连接Nebula Graph, 以及基础的增删改查操作. 
-
-## 文档
-
-按照以下步骤可以快速部署并且使用Nebula Graph. 
-
-1. [安装Nebula Graph](../4.deployment-and-installation/2.compile-and-install-nebula-graph/2.install-nebula-graph-by-rpm-or-deb.md)
-
-  使用RPM或DEB文件可以快速安装Nebula Graph. 其它部署方式及相应的准备工作请参见[安装部署](../4.deployment-and-installation/1.resource-preparations.md). 
-
-2. [启动Nebula Graph](5.start-stop-service.md)
-
-  部署好Nebula Graph之后需要启动Nebula Graph服务. 
-
-3. [连接Nebula Graph](3.connect-to-nebula-graph.md)
-
-  启动Nebula Graph服务后即可使用客户端连接. Nebula Graph支持多种客户端, 快速入门中介绍使用原生命令行客户端Nebula Console连接Nebula Graph的方法. 
-
-4. [使用常用nGQL（CRUD命令）](4.nebula-graph-crud.md)
-
-  连接到Nebula Graph之后即可使用nGQL（Nebula Graph Query Language）进行增删改查. 
-
-## 视频
-
-用户也可以观看视频了解Nebula Graph的相关概念和操作. 
-
-### 热点视频
-
-* [听吴敏博士聊Nebula Graph](https://www.bilibili.com/video/BV14U4y157zc)（37分40秒）
-
-<iframe src="//player.bilibili.com/player.html?aid=673642782&bvid=BV14U4y157zc&cid=355543912&page=1&high_quality=1" scrolling="no" border="0" frameborder="no" framespacing="0" allowfullscreen="true" width="720px" height="480px"> </iframe>
-
-* [Foesa小学姐课堂——Nebula Graph那些磨人的概念](https://www.bilibili.com/video/BV1Q5411K7Gg)（04分20秒）
-
-<iframe src="//player.bilibili.com/player.html?aid=461196353&bvid=BV1Q5411K7Gg&cid=355536579&page=1&high_quality=1" scrolling="no" border="0" frameborder="no" framespacing="0" allowfullscreen="true" width="720px" height="480px"> </iframe>
-
-* [Foesa小学姐课堂——path 的三种类型](https://www.bilibili.com/video/BV1Uf4y1t72L)（03分09秒）
-<iframe src="//player.bilibili.com/player.html?aid=291311326&bvid=BV1Uf4y1t72L&cid=361000311&page=1" scrolling="no" border="0" frameborder="no" framespacing="0" allowfullscreen="true" width="720px" height="480px"> </iframe>
-
-### 入门系列
-
-* [Nebula Graph Studio图探索](https://www.bilibili.com/video/BV1QN411Z7Vh)（03分23秒）
-
-<iframe src="//player.bilibili.com/player.html?aid=503286771&bvid=BV1QN411Z7Vh&cid=344349765&page=1&high_quality=1" scrolling="no" border="0" frameborder="no" framespacing="0" allowfullscreen="true" width="720px" height="480px"> </iframe>
-
-* [Nebula Exchange](https://www.bilibili.com/video/BV1Pq4y177D9)（03分08秒）
-
-<iframe src="//player.bilibili.com/player.html?aid=546003709&bvid=BV1Pq4y177D9&cid=352387808&page=1&high_quality=1" scrolling="no" border="0" frameborder="no" framespacing="0" allowfullscreen="true" width="720px" height="480px"> </iframe>
-
-* [Nebula Algorithm](https://www.bilibili.com/video/BV1fB4y1T7XK)（02分36秒）
-
-<iframe src="//player.bilibili.com/player.html?aid=588577467&bvid=BV1fB4y1T7XK&cid=351282857&page=1&high_quality=1" scrolling="no" border="0" frameborder="no" framespacing="0" allowfullscreen="true" width="720px" height="480px"> </iframe>
-
-### NG辅导班
-
-* [第一篇: 图世界的那些概念、术语](https://www.bilibili.com/video/BV17X4y1A7p9)（08分12秒）
-
-<iframe src="//player.bilibili.com/player.html?aid=716209223&bvid=BV17X4y1A7p9&cid=355893988&page=1&high_quality=1" scrolling="no" border="0" frameborder="no" framespacing="0" allowfullscreen="true" width="720px" height="480px"> </iframe>
-
-* [第二篇: 如何更好地学习 Nebula Graph](https://www.bilibili.com/video/BV1aX4y1A7xd)（07分44秒）
-
-<iframe src="//player.bilibili.com/player.html?aid=716219807&bvid=BV1aX4y1A7xd&cid=355896587&page=1&high_quality=1" scrolling="no" border="0" frameborder="no" framespacing="0" allowfullscreen="true" width="720px" height="480px"> </iframe>
-
-请访问[Bilibili空间](https://space.bilibili.com/472621355), 查看 30 多个, 500 多分钟的系列视频. 
-
--->

docs-2.0/2.quick-start/4.nebula-graph-crud.md

@@ -1,4 +1,4 @@
-# Step 4: Use nGQL（CRUD）
+# Step 4: Use nGQL (CRUD)
 
 This topic will describe the basic CRUD operations in Nebula Graph.