This is the performance report for NebulaGraph Community Edition v3.4.0.

In this version, NebulaGraph has added Memory Tracker and has enabled concurrent queries. 

NebulaGraph Database v3.4.0 Benchmark Report

NebulaGraph Database recently released its latest [Enterprise Edition v3.4.0](https://docs.nebula-graph.io/3.4.0/20.appendix/release-notes/nebula-ent-release-note/), further enhancing the stability and ease-of-use of the core product. In this version, the performance of deep queries is significantly optimized, more than 60% better than before, enabling enterprise users to explore the correlation value in massive data more efficiently.

# Guaranteed Security of Data Assets

As the significance of data storage and data mining increasingly matters, data security has become a top concern for enterprises. To meet this demand, NebulaGraph supports incremental backup in v3.4.0  on top of existing data recovery & backup features, ensuring data security and business continuity.

![incremental-backup](https://www-cdn.nebula-graph.io/nebula-website-5.0/images/blogs/visualization-3.4.0/1.png)

In addition, NebulaGraph also offers more fine-grained permission management in the new version through tag/edge-type level access control so that different roles in the same graph can only see the data within their limits of authority, thus protecting team collaboration security.

# Enhanced Stability and Ease-of-Use

Facing explosive data volume growth, enterprises attach great importance to real-time data queries when selecting a database.
With the latest NebulaGraph Enterprise edition, enterprises can leverage its optimized capability in high availability and stability to explore a sheer volume of connected data with milliseconds latency.


NebulaGraph Enterprise v3.4.0 adds a new black box monitoring tool, which can capture the system status at the moment of abnormality, such as core dump and crash, and pinpoint the issue with the parsing toolkits.

The new version also optimizes memory management and adds Memory Tracker to support more refined memory management control. Users can accurately track the memory resource application of each operator in each query and control it accordingly so as to reduce the probability of OOM.

Furthermore, functions like Kill Session are also added to the latest version to avoid link non-release caused by incorrect operation, which makes it more convenient for DBAs to maintain. The full-text index also becomes more efficient by streamlined deployment and usage constraints.

# Upgraded Graph Visualization Experience

NebulaGraph is committed to building an end-to-end, easy-to-use graph technology ecosystem to accelerate the application and popularization of graph technology. Now it has developed a series of graph visualization products, such as NebulaGraph Studio, NebulaGraph Explorer and NebulaGraph Dashboard, for developers and data scientists to easily explore graph data and intuitively manage NebulaGraph clusters.

NebulaGraph Dashboard, as a multi-cluster visual operation and maintenance tool developed for NebulaGraph, provides monitoring, alerting, backup, diagnosis, upgrade and expansion, which make the work of DBAs and operations personnel easier.

![NebulaGraph-dashboard](https://www-cdn.nebula-graph.io/nebula-website-5.0/images/blogs/visualization-3.4.0/nebulagraph-dashboard-overview.jpeg)


In NebulaGraph Enterprise Edition v3.4.0, NebulaGraph Dashboard adds incremental backup, runtime log, audit log, and job management functions and displays and configures multiple services. Armed with these features, DBAs and developers are able to view, pause and restore the workspace whenever needed. The new version also has a feedback portal, and users can quickly seek professional support when encountering challenging issues.

Meanwhile, other visualization tools -  NebulaGraph Studio and NebulaGraph Explorer,  are also optimized in terms of schema creation statement view, slow query optimization and significant improvement of visualization presentation effect.

# About NebulaGraph Database

As a high-performance native distributed graph database, NebulaGraph Database excels in handling mega data sets with hundreds of billions of nodes and trillions of edges, while maintaining millisecond query latency. Relying on its shared-nothing, distributed architecture and computation-and-storage separation, it is highly available, highly secure, and easy to scale out, largely meeting the security requirements of enterprises. Besides,  it can be deployed on the public cloud and on-premises as needed.

# Talk to a Graph Database Expert

Get a customized solution for your organization and see how NebulaGraph can help you:

[**Contact NebulaGraph**](https://www.nebula-graph.io/contact)



NebulaGraph Database recently released its latest Enterprise Edition v3.4.0, enabling enterprise users to explore the correlation value in massive data more efficiently.

NebulaGraph Announces General Availability of Enterprise Edition v3.4.0

Along with the release of [NebulaGraph v3.4.0](https://www.nebula-graph.io/posts/nebulagraph-v3.4.0-release-notes), its graph visualization products NebulaGraph Dashboard, NebulaGraph Explorer, and NebulaGraph Studio have also been upgraded to their latest versions. In this article, we will take a quick look at the new features of each visualization product.

# NebulaGraph Dashboard

NebulaGraph Dashboard is a powerful visualization and operations tool for the NebulaGraph database, designed to make the work of DBAs and operations personnel easier. With Dashboard, you can quickly create and import clusters and monitor them in real time, receiving alarms as needed. Additionally, the dashboard offers various operations such as cluster upgrades, scaling, backup and recovery, and service start and stop, making cluster management more straightforward and intuitive.

![NebulaGraph-Dashboard-Overview](https://www-cdn.nebula-graph.io/nebula-website-5.0/images/blogs/visualization-3.4.0/nebulagraph-dashboard-overview.jpeg)

## New Features of NebulaGraph Dashboard Enterprise Edition

* When system failures occur, troubleshooting problems by reviewing runtime logs is often necessary. The 3.4.0 version of NebulaGraph Dashboard allows viewing NebulaGraph runtime logs, quickly identifying the issues.

![run-time-log](https://www-cdn.nebula-graph.io/nebula-website-5.0/images/blogs/visualization-3.4.0/2.png)

* In addition to runtime logs, NebulaGraph Dashboard's audit log feature classifies and stores all operations the Graph service receives, making it easy to review NebulaGraph audit logs.

![audit-log](https://www-cdn.nebula-graph.io/nebula-website-5.0/images/blogs/visualization-3.4.0/3.png)

* Furthermore,  NebulaGraph Dashboard allows for visual management of long-running tasks, also known as jobs, within a specified graph space, including the ability to view, stop, resume, and view the details of individual jobs.

![job-management](https://www-cdn.nebula-graph.io/nebula-website-5.0/images/blogs/visualization-3.4.0/4.png)

* Additionally, you can also incrementally back up existing backup files on S3 through the Dashboard.

![incremental-backup](https://www-cdn.nebula-graph.io/nebula-website-5.0/images/blogs/visualization-3.4.0/1.png)


## Enhancements in NebulaGraph Dashboard Community Edition v3.4.0

- Feature
  - Support the built-in [dashboard.service](../../nebula-dashboard/2.deploy-dashboard.md) script to manage the Dashboard services with one-click and view the Dashboard version.
  - Support viewing the configuration of Meta services.

- Enhancement
  - Adjust the directory structure and simplify the [deployment steps](../../nebula-dashboard/2.deploy-dashboard.md).
  - Display the names of the monitoring metrics on the overview page of `machine`.
  - Optimize the calculation of monitoring metrics such as `num_queries`, and adjust the display to time series aggregation.
  

# NebulaGraph Explorer

NebulaGraph Explorer is a web-based visual graph exploration tool. Based on the NebulaGraph Database for visual interaction with graph data, it supports fast finding friends and neighbors,  analyzing suspicious targets, and performing graph computational analysis from complex relationships and large amounts of data.

![NebulaGraph-Explorer](https://www-cdn.nebula-graph.io/nebula-website-5.0/images/blogs/visualization-3.4.0/nebulagraph-explorer-overview.png)

![NebulaGraph-Explorer-3D](https://www-cdn.nebula-graph.io/nebula-website-5.0/images/blogs/visualization-3.4.0/nebulagraph-explorer-overview-3d.png)

* The new version of NebulaGraph Explorer supports viewing the schema creation statement for the specified graph space, and you can download the statement or copy it to the console for execution.

*  Removed the timeout limit for viewing slow queries.

This iteration of NebulaGraph Explorer places a major emphasis on product usability and visualization presentation, spending a significant amount of time polishing the functions of the explorer, hoping to help users more quickly and easily explore relationships between data. For more details, please see the [release notes](https://docs.nebula-graph.io/3.4.0/20.appendix/release-notes/explorer-release-note/).

# NebulaGraph Studio

Finally, the open-source web-based graph visualization tool NebulaGraph Studio. It now supports viewing the creation statements of Schema just like NebulaGraph Explorer. And a feedback page is integrated for easier issue collection. Besides, we have made optimization in multiple aspects and fixed some bugs, making it better than ever.


![NebulaGraph-Studio](https://www-cdn.nebula-graph.io/nebula-website-5.0/images/blogs/visualization-3.4.0/nebulagraph-studio-overview.png)

It now supports viewing the creation statements of Schema just like NebulaGraph Explorer. And a feedback page is integrated for easier issue collection. Besides, we have made optimization in multiple aspects and fixed some bugs, making it better than ever.

Get started free with the latest version of NebulaGraph Studio, click the link to download [https://github.com/vesoft-inc/nebula-studio/releases/tag/v3.6.0](https://github.com/vesoft-inc/nebula-studio/releases/tag/v3.6.0)


Are you interested in experiencing the entire NebulaGraph Database Enterprise Edition in one go? Click [here](http://nebula-graph.io/visulization-tools-free-trial) to have a 30-day free trial right away!

Along with the release of NebulaGraph v3.4.0, its graph visualization products NebulaGraph Dashboard, NebulaGraph Explorer, and NebulaGraph Studio have also been upgraded to their latest versions. In this article, we will take a quick look at the new features of each visualization product.

NebulaGraph Visualization v3.4.0 Launched to Support Incremental Backup

NebulaGraph Community Edition v3.4.0 is out. This version brings new features of Kill Sessions, Memory Tracker, and so forth, in addition to continuous stability optimization.

# Feature

- Support [killing sessions](https://docs.nebula-graph.io/3.4.0/3.ngql-guide/17.query-tuning-statements/2.kill-session/). [#5146](https://github.com/vesoft-inc/nebula/pull/5146)
- Support [Memory Tracker](https://docs.nebula-graph.io/3.4.0/5.configurations-and-logs/1.configurations/4.storage-config/) to optimize memory management. [#5082](https://github.com/vesoft-inc/nebula/pull/5082)

# Enhancement

- Optimize job management. [#5212](https://github.com/vesoft-inc/nebula/pull/5212) [#5093](https://github.com/vesoft-inc/nebula/pull/5093) [#5099](https://github.com/vesoft-inc/nebula/pull/5099) [#4872](https://github.com/vesoft-inc/nebula/pull/4872)

- Modify the default value of the Graph service parameter `session_reclaim_interval_secs` to 60 seconds. [#5246](https://github.com/vesoft-inc/nebula/pull/5246)

- Adjust the default level of `stderrthreshold` in the configuration file. [#5188](https://github.com/vesoft-inc/nebula/pull/5188)

- Optimize the full-text index. [#5077](https://github.com/vesoft-inc/nebula/pull/5077) [#4900](https://github.com/vesoft-inc/nebula/pull/4900) [#4925](https://github.com/vesoft-inc/nebula/pull/4925)

- Limit the maximum depth of the plan tree in the optimizer to avoid stack overflows. [#5050](https://github.com/vesoft-inc/nebula/pull/5050)

- Optimize the treatment scheme when the pattern expressions are used as predicates. [#4916](https://github.com/vesoft-inc/nebula/pull/4916)

# Bugfix

- Fix the bug about query plan generation and optimization. [#4863](https://github.com/vesoft-inc/nebula/pull/4863) [#4813](https://github.com/vesoft-inc/nebula/pull/4813)

- Fix the bugs related to indexes:

  - Full-text indexes [#5214](https://github.com/vesoft-inc/nebula/pull/5214) [#5260](https://github.com/vesoft-inc/nebula/pull/5260)
  - String indexes [5126](https://github.com/vesoft-inc/nebula/pull/5126)

- Fix the bugs related to query statements:

  - Variables [#5192](https://github.com/vesoft-inc/nebula/pull/5192)
  - Filter conditions and expressions [#4952](https://github.com/vesoft-inc/nebula/pull/4952) [#4893](https://github.com/vesoft-inc/nebula/pull/4893) [#4863](https://github.com/vesoft-inc/nebula/pull/4863)
  - Properties of vertices or edges [#5230](https://github.com/vesoft-inc/nebula/pull/5230) [#4846](https://github.com/vesoft-inc/nebula/pull/4846) [#4841](https://github.com/vesoft-inc/nebula/pull/4841) [#5238](https://github.com/vesoft-inc/nebula/pull/5238)
  - Functions and aggregations [#5135](https://github.com/vesoft-inc/nebula/pull/5135) [#5121](https://github.com/vesoft-inc/nebula/pull/5121) [#4884](https://github.com/vesoft-inc/nebula/pull/4884)
  - Using illegal data types [#5242](https://github.com/vesoft-inc/nebula/pull/5242)
  - Clauses and operators [#5241](https://github.com/vesoft-inc/nebula/pull/5241) [#4965](https://github.com/vesoft-inc/nebula/pull/4965)

- Fix the bugs related to DDL and DML statements:

  - ALTER TAG [#5105](https://github.com/vesoft-inc/nebula/pull/5105) [#5136](https://github.com/vesoft-inc/nebula/pull/5136)
  - UPDATE [#4933](https://github.com/vesoft-inc/nebula/pull/4933)

- Fix the bugs related to other functions:

  - TTL [#4961](https://github.com/vesoft-inc/nebula/pull/4961)
  - Authentication [#4885](https://github.com/vesoft-inc/nebula/pull/4885)
  - Services [#4896](https://github.com/vesoft-inc/nebula/pull/4896)

# Change

- The added property name can not be the same as an existing or deleted property name, otherwise, the operation of adding a property fails. [#5130](https://github.com/vesoft-inc/nebula/pull/5130)
- Limit the type conversion when modifying the schema. [#5098](https://github.com/vesoft-inc/nebula/pull/5098)
- The default value must be specified when creating a property of type `NOT NULL`. [#5105](https://github.com/vesoft-inc/nebula/pull/5105)
- Add the multithreaded query parameter `query_concurrently` to  the configuration file with a default value of `true`. [#5119](https://github.com/vesoft-inc/nebula/pull/5119)
- Remove the parameter `kv_separation` of the KV separation storage function from the configuration file, which is turned off by default. [#5119](https://github.com/vesoft-inc/nebula/pull/5119)
- Modify the default value of `local_config` in the configuration file to `true`. [#5119](https://github.com/vesoft-inc/nebula/pull/5119)
- Consistent use of `v.tag.property` to get property values, because it is necessary to specify the Tag. Using `v.property` to access the property of a Tag on `v` was incorrectly allowed in the previous version. [#5230](https://github.com/vesoft-inc/nebula/pull/5230)
- Remove the column `HTTP port` from the command `SHOW HOSTS`. [#5056](https://github.com/vesoft-inc/nebula/pull/5056)
- Disable the queries of the form `OPTIONAL MATCH <pattern> WHERE <condition>`. [#5273](https://github.com/vesoft-inc/nebula/pull/5273)
- Disable TOSS. [#5119](https://github.com/vesoft-inc/nebula/pull/5119)
- Rename Listener's pid filename and log directory name. [#5119](https://github.com/vesoft-inc/nebula/pull/5119)

# Notes for upgrading

To upgrade to v3.4.0, follow the upgrade guide:

- [Upgrade NebulaGraph from v2.x to v3.4.0](../../4.deployment-and-installation/3.upgrade-nebula-graph/upgrade-nebula-graph-to-latest.md)
- [Upgrade NebulaGraph from v3.x to v3.4.0](../../4.deployment-and-installation/3.upgrade-nebula-graph/upgrade-nebula-from-300-to-latest.md)
  

>If you encounter any problems in the process of using NebulaGraph, please refer to [NebulaGraph Database Manual ](https://docs.nebula-graph.io/3.4.0/20.appendix/release-notes/nebula-comm-release-note/)to troubleshoot the problem. It records in detail the knowledge points and specific usage of the graph database and the graph database NebulaGraph.

>Join our [Slack channel](https://join.slack.com/t/nebulagraph/shared_invite/zt-7ybejuqa-NCZBroh~PCh66d9kOQj45g) if you want to discuss with the rest of the NebulaGraph community!





NebulaGraph Database v3.4.0 brings new features of Kill Sessions, Memory Tracker, and so forth, in addition to continuous stability optimization.

 NebulaGraph Database v3.4.0 Release Note


![NebulaGraph v3.0.0 Release Note](https://user-images.githubusercontent.com/90186547/154224692-2244e379-843b-4046-958d-3e672c304c90.jpg)

NebulaGraph v3.0.0 is here! The new version introduced a series of new features including enhanced backup and restore, better support for the openCypher query language, and more fine-grained user management.

# Features

* Support backup and restore. [#3469](https://github.com/vesoft-inc/nebula/pull/3469) [#1](https://github.com/vesoft-inc/nebula-agent/pull/1) [#22](https://github.com/vesoft-inc/nebula-br/pull/22)

* Support openCypher queries with multiple `MATCH` statements. [#3519](https://github.com/vesoft-inc/nebula/pull/3519) [#3318](https://github.com/vesoft-inc/nebula/pull/3318)

* Support Standalone NebulaGraph. [#3310](https://github.com/vesoft-inc/nebula/pull/3310)

* Support key value separation for the storage engine. [#3281](https://github.com/vesoft-inc/nebula/pull/3281)

* Support topN push down for `LOOKUP`. [#3499](https://github.com/vesoft-inc/nebula/pull/3499)

* Support vertex without tag. [#3316](https://github.com/vesoft-inc/nebula/pull/3316) [#3335](https://github.com/vesoft-inc/nebula/pull/3335) [#3328](https://github.com/vesoft-inc/nebula/pull/3328) [#3286](https://github.com/vesoft-inc/nebula/pull/3286)

* Support parameterized queries. [#3379](https://github.com/vesoft-inc/nebula/pull/3379)

* Support queries without specifying VIDs but a `LIMIT` clause must be used to restrict the number of results. [#3320](https://github.com/vesoft-inc/nebula/pull/3320) [#3329](https://github.com/vesoft-inc/nebula/pull/3329) [#3262](https://github.com/vesoft-inc/nebula/pull/3262)

* Support duration. [#3338](https://github.com/vesoft-inc/nebula/pull/3338)

* Support most UTF-8 encoded characters of 1 to 4 bytes in Schema.  [#3380](https://github.com/vesoft-inc/nebula/pull/3380) [#3440](https://github.com/vesoft-inc/nebula/pull/3440)

* Support `DESCRIBE USER`.  [#3300](https://github.com/vesoft-inc/nebula/pull/3300)

# Optimizations

- Refactor cluster management. [#3343](https://github.com/vesoft-inc/nebula/pull/3343)

- Add log monitor to check free bytes for log disks, change log level when your graph space is almost full. [#3576](https://github.com/vesoft-inc/nebula/pull/3576)

- Support any string for tag names in apostrophe. [#3424](https://github.com/vesoft-inc/nebula/pull/3424)

- Support that the storage service sends partition disk paths to the meta. [#3369](https://github.com/vesoft-inc/nebula/pull/3369) [#3416](https://github.com/vesoft-inc/nebula/pull/3416)

- Add constraints on invalid password attempts. [#3573](https://github.com/vesoft-inc/nebula/pull/3573) [#3629](https://github.com/vesoft-inc/nebula/pull/3629)

- Support `DELETE` in TOSS. [#3374](https://github.com/vesoft-inc/nebula/pull/3374)

- Support to use logrotate. [#3541](https://github.com/vesoft-inc/nebula/pull/3541)

- Support more metrics. [#3446](https://github.com/vesoft-inc/nebula/pull/3446) [#3605](https://github.com/vesoft-inc/nebula/pull/3605) [#3590](https://github.com/vesoft-inc/nebula/pull/3590)

- Enhancement date and time parser. [#3179](https://github.com/vesoft-inc/nebula/pull/3179)

- Remove read lock in the meta service to reduce the side effect of read-write locks. [#3256](https://github.com/vesoft-inc/nebula/pull/3256)

- Refactor storage indexes to solve the coupling problem between services. [#3196](https://github.com/vesoft-inc/nebula/pull/3196)

- Support specifying the floating point accuracy of the `round()` function. [#3178](https://github.com/vesoft-inc/nebula/pull/3178)ß

- Support HTTPS for the ES client. [#3150](https://github.com/vesoft-inc/nebula/pull/3150)

- Move version info outside of heartbeat. [#3378](https://github.com/vesoft-inc/nebula/pull/3378)

- Support empty list, set, and map. [#3302](https://github.com/vesoft-inc/nebula/pull/3302)

- Support specifying s2 region coverage parameters when creating a geo index. [#3396](https://github.com/vesoft-inc/nebula/pull/3396)

- Add version info for `SHOW HOSTS`. [#3702](https://github.com/vesoft-inc/nebula/pull/3702)

# Bugfix

* Fix the bug that memory is not released when a default value is used and no value is specified in nGQL. [#3666](https://github.com/vesoft-inc/nebula/pull/3666)

- Fix the bug that the function `coalesce()` cannot be used. [#3653](https://github.com/vesoft-inc/nebula/pull/3653)

- Fix the bug that using multiple INSERT on an indexed tag will lead to incorrect LOOKUP results. [#3627](https://github.com/vesoft-inc/nebula/pull/3627)

- Fix the crash when the expression exceeds the depth. [#3606](https://github.com/vesoft-inc/nebula/pull/3606)

- Disable the aggregate function in the `YIELD` and `WHERE` clauses of nGQL. [#3597](https://github.com/vesoft-inc/nebula/pull/3597)

- Fix the crash when using the aggregate function in `UNWILD` and `WHERE` clauses. [#3397](https://github.com/vesoft-inc/nebula/pull/3397) [#3355](https://github.com/vesoft-inc/nebula/pull/3355)

- Fix the bug that the tag index is rebuilt with an old schema version value. [#3332](https://github.com/vesoft-inc/nebula/pull/3332)

- Fix the bug that the query results will still contain the expired edges if we use `GO...REVERSELY`. [#3536](https://github.com/vesoft-inc/nebula/pull/3536)

- Fix the memory estimation error info in CentOS 6.0. [#3534](https://github.com/vesoft-inc/nebula/pull/3534)

- Fix the crash when the `LOOKUP` statement contains a filter that consists of a logical And expression and an IN expression with only one element. [#3525](https://github.com/vesoft-inc/nebula/pull/3525)

- Fix the bug that metad progress is suspended under heavy load. [#3482](https://github.com/vesoft-inc/nebula/pull/3482)

- Fix the unwinding subgraph crash. [#3506](https://github.com/vesoft-inc/nebula/pull/3506)

- Fix the `DROP SPACE` crash when rebuilding an index. [#3406](https://github.com/vesoft-inc/nebula/pull/3406)

- Fix the bug of reading memory stats under cgroup v2. [#3419](https://github.com/vesoft-inc/nebula/pull/3419)

- Fix the bug that `DROP TAG INDEX` deletes the edge index with the same name unexpectedly, and vice versa for the deletion of the tag index. [#3413](https://github.com/vesoft-inc/nebula/pull/3413)

- Fix the bug that edges are not shown after a graph space is cloned. [#3351](https://github.com/vesoft-inc/nebula/pull/3351)

- Fix the index existence check problem. [#3315](https://github.com/vesoft-inc/nebula/pull/3315)

- Fix a bug that running the `ALTER` statement to query the type property may lead to a null pointer obtained by the graph service. [#3325](https://github.com/vesoft-inc/nebula/pull/3325)

- Optimized the Raft to make the system more stable. [#3172](https://github.com/vesoft-inc/nebula/pull/3172) [#3435](https://github.com/vesoft-inc/nebula/pull/3435) [#3358](https://github.com/vesoft-inc/nebula/pull/3358) [#3322](https://github.com/vesoft-inc/nebula/pull/3322) [#3031](https://github.com/vesoft-inc/nebula/pull/3031)

- Cancel memory check when the ratio is greater than 1.0. [#3289](https://github.com/vesoft-inc/nebula/pull/3289)

- Fix the error with ninja-build. [#3195](https://github.com/vesoft-inc/nebula/pull/3195)

- Fix the bug that creating tag and edge with the same name at the same time may both succeed. [#3735](https://github.com/vesoft-inc/nebula/pull/3735)

- Fix the full-text index creation failure when there are the same tags or edges in different spaces. [#3747](https://github.com/vesoft-inc/nebula/pull/3747)

- Fix variable inconsistency in `YIELD` clauses and `GO` statements. [#3430](https://github.com/vesoft-inc/nebula/pull/3430)

- Fix the crash when schema version is greater than 256. [#3893](https://github.com/vesoft-inc/nebula/pull/3893)

# Incompatibility

* NebulaGraph 3.0.0 does not support most ecosystem tools of v2.x, please upgrade the [ecosystem tools](https://docs.nebula-graph.io/3.0.1/20.appendix/6.eco-tool-version/).

- Storage services defined in the configuration files cannot be read or written directly. The configuration files only register the storage services into the meta services. You must run the `ADD HOSTS` command to read and write data on storage servers. [#3343](https://github.com/vesoft-inc/nebula/pull/3343)

- Disable ZONE and GROUP. [#3776](https://github.com/vesoft-inc/nebula/pull/3776) [#3825](https://github.com/vesoft-inc/nebula/pull/3825) [#3330](https://github.com/vesoft-inc/nebula/pull/3330)

- Disable `BALANCE DATA`. [#3756](https://github.com/vesoft-inc/nebula/pull/3756)

- Modify the default session timeout from `0` to `28800` seconds, limit the value to between `1` and `604800` seconds. [#3357](https://github.com/vesoft-inc/nebula/pull/3357) [#3807](https://github.com/vesoft-inc/nebula/pull/3807)

- Add `SHOW LOCAL SESSIONS` and `SHOW LOCAL QUERIES` commands, and deprecate `SHOW ALL QUERIES`. [#3488](https://github.com/vesoft-inc/nebula/pull/3488)

- A tag is not required for a vertex. `DELETE VERTEX` only deletes the vertices and does not delete the related outgoing and incoming edges of the vertices. At this time, there will be hanging edges by default. [#3316](https://github.com/vesoft-inc/nebula/pull/3316) [#3335](https://github.com/vesoft-inc/nebula/pull/3335) [#3328](https://github.com/vesoft-inc/nebula/pull/3328) [#3286](https://github.com/vesoft-inc/nebula/pull/3286)

- Disable the `YIELD` clause to return custom variables. [#3271](https://github.com/vesoft-inc/nebula/pull/3271)

- The `YIELD` clause is required in the `FETCH`, `GO`, `LOOKUP`, `FIND PATH` and `GET SUBGRAPH` statements. [#2957](https://github.com/vesoft-inc/nebula/pull/2957) [#3056](https://github.com/vesoft-inc/nebula/pull/3056) [#3139](https://github.com/vesoft-inc/nebula/pull/3139)

- Add non-reserved keywords: `s2_max_level`, `s2_max_cells`. [#3396](https://github.com/vesoft-inc/nebula/pull/3396)

- It is required to specify a tag to query properties of a vertex in a `MATCH` statement. For example, from `return v.name` to `return v.player.name`. [#3255](https://github.com/vesoft-inc/nebula/pull/3255)

If you encounter any problems in the process of using NebulaGraph, please refer to [NebulaGraph Database Manual](https://docs.nebula-graph.io/3.0.1/pdf/NebulaGraph-EN.pdf) to troubleshoot the problem. It records in detail the knowledge points and specific usage of the graph database and the graph database NebulaGraph.

Join our [Slack channel](https://join.slack.com/t/nebulagraph/shared_invite/zt-7ybejuqa-NCZBroh~PCh66d9kOQj45g) if you want to discuss with the rest of the NebulaGraph community!

NebulaGraph v3.0.0 is here! The new version introduced a series of new features including enhanced backup and restore, better support for the openCypher query language, and more fine-grained user management.

NebulaGraph v3.0.0 Release Note

NebulaGraph v2.6 has just released. In this version, functions such as TOSS, ZONE, Geo Spatial, transmission intelligence, and JSON format return etc. have been added, and the computation of index scan limit pushdown, YIELD data format, memory watermark detection and other functions have been optimized. Also, some bugs have been fixed.

# New Features

* Support TOSS 

https://github.com/vesoft-inc/nebula/pull/2525


* Support ZONE

https://github.com/vesoft-inc/nebula/issues/2604

* Support Geo Spatial 

https://github.com/vesoft-inc/nebula/pull/2954 
https://github.com/vesoft-inc/nebula/pull/2979
https://github.com/vesoft-inc/nebula/pull/3043

* Support crypto in transmission

https://github.com/vesoft-inc/nebula/pull/2584

* Support to return query result as JSON format

https://github.com/vesoft-inc/nebula/pull/2824

* Support to clone space meta

https://github.com/vesoft-inc/nebula/pull/2763

* Support indexScan when using IN expressions in LOOKUP

https://github.com/vesoft-inc/nebula/pull/2906

* Integration Breakpad

https://github.com/vesoft-inc/nebula/pull/2536

* Support to copy the local folder of metad to remote

https://github.com/vesoft-inc/nebula/pull/2532

* Support DELETE TAG

https://github.com/vesoft-inc/nebula/pull/2520

* Support concat function

https://github.com/vesoft-inc/nebula/pull/2540

* Support SHOW META LEADER

https://github.com/vesoft-inc/nebula/pull/2542

# Improvements

* Optimize the computation of index scan limit pushdown

https://github.com/vesoft-inc/nebula/pull/2905 https://github.com/vesoft-inc/nebula/pull/2823 https://github.com/vesoft-inc/nebula/pull/2796

* Optimize the calculation of sampling and limit pushdown at each step of the go statement

https://github.com/vesoft-inc/nebula/pull/2904 https://github.com/vesoft-inc/nebula/pull/2853 https://github.com/vesoft-inc/nebula/pull/2831

* Better yield data format

https://github.com/vesoft-inc/nebula/pull/2555 https://github.com/vesoft-inc/nebula/pull/2572 https://github.com/vesoft-inc/nebula/pull/2779 https://github.com/vesoft-inc/nebula/pull/2895 https://github.com/vesoft-inc/nebula/pull/2944

* Enable prefix bloom filter by default to improve performance

https://github.com/vesoft-inc/nebula/pull/2860

* Support server to verify client version to make sure the connection reliability(client version start from v2.6.0)

https://github.com/vesoft-inc/nebula/pull/2965

* Optimize flow control when pulling the entire partition

https://github.com/vesoft-inc/nebula/pull/2557

* SHOW JOBS only show space related

https://github.com/vesoft-inc/nebula/pull/2872

* Grant job permission for all roles except GUEST

https://github.com/vesoft-inc/nebula/pull/2928

* Improve memory watermark detection

https://github.com/vesoft-inc/nebula/pull/2885

* Support to kill the slow queries of storage 

https://github.com/vesoft-inc/nebula/pull/2534

# Bugfix

* Fixed the bug that part of RocksDB data is cleaned when executing `raftpart::reset`

https://github.com/vesoft-inc/nebula/pull/2522

* Fixed the bug that the nebula connection will be interrupted if the YIELD clause in LOOKUP contains aggregate function

https://github.com/vesoft-inc/nebula/pull/3245

* Fixed the bug that mismatched dates are inserted

https://github.com/vesoft-inc/nebula/pull/2527

* Fixed the bug that setting millisecond failed but microsecond worked

https://github.com/vesoft-inc/nebula/pull/2781

* Fixed the bug that the Meta service crashed when too much data (millions of lines) are inserted in batches

https://github.com/vesoft-inc/nebula/pull/2813

* Fixed the bug that getting edges crashed when no edge schema exists in SPACE

https://github.com/vesoft-inc/nebula/pull/2571

* Fixed the bug that GO with WHERE clause expression eval when the property data type is `FIXED_STRING`

https://github.com/vesoft-inc/nebula/pull/2762

* Fixed the bug of FIND ALL PATH

https://github.com/vesoft-inc/nebula/pull/2773

* Fixed the bug that users without roles have the permission to find all roles of SPACE

https://github.com/vesoft-inc/nebula/pull/2778

* Fixed the bug of the case expression

https://github.com/vesoft-inc/nebula/pull/2819

* Fixed the bug that the infinite loop is returned when using time()

https://github.com/vesoft-inc/nebula/pull/2820

* Fixed the bug that the JOB is still running when the node is already shut down

https://github.com/vesoft-inc/nebula/pull/2843

* Fixed the bug that `INSERT` statements may cause inconsistent property values between replicas in the case of multiple replicas

https://github.com/vesoft-inc/nebula/pull/2862

* Fixed the bug that SPACE goes wrong when submit job after USE

https://github.com/vesoft-inc/nebula/pull/3010

* Fixed the bug that getting attribute error of the thrift structure failed when column is not nullable

https://github.com/vesoft-inc/nebula/issues/3011

* Fixed the bug that graphd is still running even if the meta service is not ready

https://github.com/vesoft-inc/nebula/issues/3048

* Fixed the bug that dangling edge returns a null vertex when using `FIND PATH WITH PROP`

https://github.com/vesoft-inc/nebula/pull/3008

* Fixed the bug that executing `YIELD DISTINCT` map crashes 

https://github.com/vesoft-inc/nebula/pull/3051

* Fixed the bug that the service can still start with a wrong ip/host 

https://github.com/vesoft-inc/nebula/pull/3057

* Fixed the bug that repeatedly modifying the same property in one statement returns an error 

https://github.com/vesoft-inc/nebula/pull/3036

* Fixed the bug that the multi-step filtering on edge is invalid

https://github.com/vesoft-inc/nebula/pull/3144

If you encounter any problems in the process of using Nebula Graph, please refer to [NebulaGraph Database Manual](https://docs.nebula-graph.io/3.0.1/pdf/NebulaGraph-EN.pdf) to troubleshoot the problem. It records in detail the knowledge points and specific usage of the graph database and the graph database Nebula Graph.

Join our [Slack channel](https://join.slack.com/t/nebulagraph/shared_invite/zt-7ybejuqa-NCZBroh~PCh66d9kOQj45g) if you want to discuss with the rest of the NebulaGraph community!

NebulaGraph v2.6 has just released. In this version, functions such as TOSS, ZONE, Geo Spatial, transmission intelligence, and JSON format return etc. have been added, and the computation of index scan limit pushdown, YIELD data format, memory watermark detection and other functions have been optimized. Also, some bugs have been fixed.

NebulaGraph v2.6 Release Note


![v2.0.1 Release note](https://user-images.githubusercontent.com/57335825/115352166-9ee21280-a1e9-11eb-99bf-941af1e50f7e.png)

NebulaGraph v2.0.1 has just been released. This version has mainly improved the performance of NebulaGraph. It has also fixed some bugs.

Check out the new features and improvements in detail below.

# Improvements

- Optimize the performance of `StorageClient` [https://github.com/vesoft-inc/nebula-common/pull/468](https://github.com/vesoft-inc/nebula-common/pull/468)
- HTTP `GetFlags` interface adds support for Unsigned Integers [https://github.com/vesoft-inc/nebula-common/pull/469](https://github.com/vesoft-inc/nebula-common/pull/469) 
- Add check for Raft Listener and Storage Service IP/Port conflicts [https://github.com/vesoft-inc/nebula-graph/pull/875](https://github.com/vesoft-inc/nebula-graph/pull/875) [https://github.com/vesoft-inc/nebula-common/pull/470](https://github.com/vesoft-inc/nebula-common/pull/470)

# Bugfix

- Fix the issue that the `GO` statement fails to yield the source vertex properties [https://github.com/vesoft-inc/nebula-graph/pull/859](https://github.com/vesoft-inc/nebula-graph/pull/859)
- Fix the issue that the services may fail to start when the `logs` directory does not exist [https://github.com/vesoft-inc/nebula-graph/pull/873](https://github.com/vesoft-inc/nebula-graph/pull/873) [https://github.com/vesoft-inc/nebula-storage/pull/403](https://github.com/vesoft-inc/nebula-storage/pull/403)
- Fix the issue that `FIND SHORTEST PATH xxx UPTO N STEPS` return N+1 steps' path when N is an odd number [https://github.com/vesoft-inc/nebula-graph/pull/912](https://github.com/vesoft-inc/nebula-graph/pull/912)
- Fix the issue when taking the output of a query as the input of the `DELETE` statement, `SementicError` is returned [https://github.com/vesoft-inc/nebula-graph/pull/917](https://github.com/vesoft-inc/nebula-graph/pull/917)
- Fix the issue that the return value of the aggregation function is inconsistent with `openCypher` if no item is found [https://github.com/vesoft-inc/nebula-graph/pull/901](https://github.com/vesoft-inc/nebula-graph/pull/901) [https://github.com/vesoft-inc/nebula-common/pull/480](https://github.com/vesoft-inc/nebula-common/pull/480)
- Fix the issue that `GetNeighborsIter()` may return partial results in cluster mode [https://github.com/vesoft-inc/nebula-graph/pull/922](https://github.com/vesoft-inc/nebula-graph/pull/922)
- Fix the issue that illegal filtering of aggregate functions in the "MATCH ... WHERE" clause makes `graphd` crash. [https://github.com/vesoft-inc/nebula-graph/pull/919](https://github.com/vesoft-inc/nebula-graph/pull/919)
- Fix `SemanticError` problem when seeking by negative vid [https://github.com/vesoft-inc/nebula-graph/pull/932](https://github.com/vesoft-inc/nebula-graph/pull/932)
- Fix the issue that the `TAG/EDGE` specification does not work in `SHOW CREATE TAG/EDGE INDEX` clauses [https://github.com/vesoft-inc/nebula-graph/pull/933](https://github.com/vesoft-inc/nebula-graph/pull/933) [https://github.com/vesoft-inc/nebula-storage/pull/426](https://github.com/vesoft-inc/nebula-storage/pull/426)
- Fix the issue that `REBUILD INDEX` returns succeed even if failed sometimes [https://github.com/vesoft-inc/nebula-storage/pull/405](https://github.com/vesoft-inc/nebula-storage/pull/405)
- Fix the issue that the indexes of newly inserted data may fail to update during the rebuilding index process [https://github.com/vesoft-inc/nebula-storage/pull/408](https://github.com/vesoft-inc/nebula-storage/pull/408)
- Fix the issue that using `NULL` in `substr()` or `substring()` makes `graphd` crash [https://github.com/vesoft-inc/nebula-common/pull/491](https://github.com/vesoft-inc/nebula-common/pull/491)

# How to Upgrade

If you are using the NebulaGraph v2.0 GA version, please follow the steps below to upgrade:

- Stop all Nebula services
    - Execute `scripts/nebula.service stop all` on each machine
    - Execute `scripts/nebula.service status  all` to ensure that all processes have exited
- Install the new RPM package on each machine per your system environment
    - Get the package：[https://github.com/vesoft-inc/nebula-graph/releases/tag/v2.0.1](https://github.com/vesoft-inc/nebula-graph/releases/tag/v2.0.1)
    - Install the package
- Start Nebula
    - Execute `scripts/nebula.service start all` on each machine
    - Execute `scripts/nebula.service status all` to ensure that all processes have started properly

If you are using other versions of NebulaGraph, please refer to [how to upgrade](https://docs.nebula-graph.io/2.0/4.deployment-and-installation/3.upgrade-nebula-graph) to first upgrade to v2.0 GA and then follow the steps above to upgrade from v2.0 GA to v2.0.1.

If you have any problem, please head over to the [Discussions](https://github.com/vesoft-inc/nebula/discussions) for discussion.

NebulaGraph v2.0.1 has just been released. This version has mainly improved the performance of NebulaGraph. It has also fixed some bugs.

NebulaGraph v2.0.1 Release Note


![NebulaGraph v1.2.1 release note](https://user-images.githubusercontent.com/57335825/115350948-49593600-a1e8-11eb-9162-06941ff5edd5.png)

NebulaGraph v1.2.1 mainly has enhanced the `LOOKUP` statement and improved the performance. And also has fixed some bugs.

# New Features

- `YIELD` clause supports `DISTINCT` [https://github.com/vesoft-inc/nebula/pull/2368](https://github.com/vesoft-inc/nebula/pull/2368)
- Add `lookup_concurrently` option. `LOOKUP` supports traversing all partitions concurrently, which improves the performance significantly. [https://github.com/vesoft-inc/nebula/pull/2417](https://github.com/vesoft-inc/nebula/pull/2417)
- `LOOKUP` clause supports `DISTINCT`. `LOOKUP ON` supports returning srcid and dstid of an edge. [https://github.com/vesoft-inc/nebula/pull/2415](https://github.com/vesoft-inc/nebula/pull/2415)

# Bugfix

- Fix the issue that `YIELD -1*1` may result in an overflow. [https://github.com/vesoft-inc/nebula/pull/2411](https://github.com/vesoft-inc/nebula/pull/2411)
- Fix the issue that leader election may be unstable when RPC times out. [https://github.com/vesoft-inc/nebula/pull/2419](https://github.com/vesoft-inc/nebula/pull/2419)
- Fix UnaryExpression bug which causes storaged crash. [https://github.com/vesoft-inc/nebula/pull/2412](https://github.com/vesoft-inc/nebula/pull/2412)
- Fix the issue `LIMIT` and `OFFSET` do not return the expected result. [https://github.com/vesoft-inc/nebula/pull/2428](https://github.com/vesoft-inc/nebula/pull/2428)
- Fix the issue that partial results may return after the leader change. [https://github.com/vesoft-inc/nebula/pull/2465](https://github.com/vesoft-inc/nebula/pull/2465)
- Fix the issue that executing `FETCH PROP ON *`  may lead to graphd crash after altering schema. [https://github.com/vesoft-inc/nebula/pull/2461](https://github.com/vesoft-inc/nebula/pull/2461)

# Changelog

- Remove option `check_leader`. Metaclient always gets the meta info from the leader server. [https://github.com/vesoft-inc/nebula/pull/2403](https://github.com/vesoft-inc/nebula/pull/2403)，[https://github.com/vesoft-inc/nebula/pull/2423](https://github.com/vesoft-inc/nebula/pull/2423)

# Upgrade Steps

- Stop all Nebula services
    - Execute `scripts/nebula.service stop all` on each machine
    - Execute `scripts/nebula.service status  all` to ensure that all processes have exited
- Install the new RPM package on each machine per your system environment
    - Get the package：[https://github.com/vesoft-inc/nebula/releases/tag/v1.2.1](https://github.com/vesoft-inc/nebula/releases/tag/v1.2.1)
    - Install the package
- Start Nebula
    - Execute `scripts/nebula.service start all` on each machine
    - Execute `scripts/nebula.service status all` to ensure that all processes have started properly

Note: If you are currently using NebulaGraph v1.0.0-RC3 or a previous version, please re-load your data after upgrading to v1.2.1.

Here is the GitHub repo of NebulaGraph: [https://github.com/vesoft-inc/nebula](https://github.com/vesoft-inc/nebula). Please feel free to try the latest version. 

If you encounter any problem, please ask on our [Discussions:](https://github.com/vesoft-inc/nebula/discussions)

NebulaGraph v1.2.1 has just been released. This version mainly has enhanced the `LOOKUP` statement and improved the performance. And also has fixed some bugs.

NebulaGraph v1.2.1 Release Note


![v2.0 GA Release note](https://user-images.githubusercontent.com/57335825/112450481-69373e80-8d8f-11eb-9e86-a7e1984df6b6.png)

NebulaGraph 2.0 GA is here! In this version, nGQL expression capability has been improved; the performance of data inserts with index has also been enhanced. NebulaGraph is gradually compatible with openCypher starting from this version.

Check out the new features and improvements in detail below.

# New Features

- `vertexID` supports both `Integer` and `String`.
- New data types:
    - NULL: the property can be set to `NULL`. `NOT NULL` constraint is also supported
    - Composite types: LIST, SET, and MAP(Cannot be set as property types)
    - Temporal types: DATE and DATETIME.
    - FIXED_STRING: a fixed size `String`
- Full-text indexes are supported to do prefix, wildcard, regex, and fuzzy search on a string property.
- Explain & Profile outputs the execution plan of an nGQL statement and execution profile.
- Subgraph to retrieve vertices and edges reachable from the start vertices.
- Support to collect statistics of the graph space.
- OpenCypher compatibility
    - Partially support the `MATCH` clause
    - Support `RETURN`, `WITH`, `UNWIND`, `LIMIT` & `SKIP` clauses
- More built-in functions
    - Predicate functions
    - Scalar functions
    - List functions
    - Aggregating functions
    - Mathematical functions
    - String functions
    - Temporal functions

# Improvements

- Optimize the performance of inserting, updating, and deleting data with indexes.
- `LOOKUP ON` filtering data supports `OR` and `AND` operators.
- `FIND PATH` supports finding paths with or without regard to direction, and also supports excluding cycles in paths.
- `SHOW HOSTS graph/meta/storage` supports to retrieve the basic information of graphd/metad/storaged hosts.

# Changelog

- The data type of `vertexID` must be specified when creating a graph space.
- `FETCH PROP ON` returns a composite object if not specify the result set.
- Changed the default port numbers of `metad`, `graphd`, and `storaged`.
- Refactor metrics counters.

# Nebula-graph Console

- Supports local commands mode. `:set csv` outputs the query results to the console and the specified CSV file. For more information, please refer to [nebula-console](https://github.com/vesoft-inc/nebula-console).


# Clients

Support connection pool and load balance.

- [cpp client](https://github.com/vesoft-inc/nebula-cpp)
- [java client](https://github.com/vesoft-inc/nebula-java)
- [python client](https://github.com/vesoft-inc/nebula-python)
- [go client](https://github.com/vesoft-inc/nebula-go)

# NebulaGraph Studio

With Studio, you can create a graph schema, load data, execute nGQL statements, and explore graphs in one stop. For more information, please refer to [nebula-web-docker](https://github.com/vesoft-inc/nebula-web-docker).

# Known Issues

- https://github.com/vesoft-inc/nebula-graph/issues/860

# How to Upgrade

Please refer to [how to upgrade](https://docs.nebula-graph.io/2.0/4.deployment-and-installation/3.upgrade-nebula-graph).

If you have any problem, please head over to the [Discussions](https://github.com/vesoft-inc/nebula/discussions) for discussion.

NebulaGraph 2.0 GA is here! In this version, nGQL expression capability has been improved; the performance of data inserts with index has also been enhanced. NebulaGraph is gradually compatible with openCypher starting from this version.

NebulaGraph v2.0 GA Release Note


![NebulaGraph v1.2.0 release note](https://user-images.githubusercontent.com/57335825/101614484-dc27cf80-39c1-11eb-9555-e7598b59c083.png)

NebulaGraph v1.2.0 has just released. In this version, the `FIND PATH` feature has been enhanced; the `DELETE` function has been optimized. Also, we have fixed some bugs.

# New Features

- `FIND PATH` support to find paths with or without regard to direction.  And also support to exclude loops in paths. [https://github.com/vesoft-inc/nebula/pull/2398](https://github.com/vesoft-inc/nebula/pull/2398)
- Add ARM64 support to NebulaGraph.[https://github.com/vesoft-inc/nebula/pull/2392](https://github.com/vesoft-inc/nebula/pull/2392)
- Add auto_remove_invalid_space option to indicate whether to remove data from a deleted graph space when restarting the services. [https://github.com/vesoft-inc/nebula/pull/2375](https://github.com/vesoft-inc/nebula/pull/2375), [https://github.com/vesoft-inc/nebula-docs/pull/196](https://github.com/vesoft-inc/nebula-docs/pull/196)

# Improvements

- Improve the `DELETE` edges performance. [https://github.com/vesoft-inc/nebula/pull/2404](https://github.com/vesoft-inc/nebula/pull/2404)

# Bugfix

- Fix the issue that `FETCH PROP ON` timestamp properties returns an `int64` value. [https://github.com/vesoft-inc/nebula/pull/2389](https://github.com/vesoft-inc/nebula/pull/2389)
- Fix the issue that `GO m TO n STEPS` may lead to OOM errors. [https://github.com/vesoft-inc/nebula/pull/2386](https://github.com/vesoft-inc/nebula/pull/2386)
- Fix the issue that `FETCH PROP ON *` might return the wrong results when the tag on the vertex has no properties. [https://github.com/vesoft-inc/nebula/pull/2359](https://github.com/vesoft-inc/nebula/pull/2359)

# Upgrade Steps

- Stop all Nebula services
    - Execute `scripts/nebula.service stop all` on each machine
    - Execute `scripts/nebula.service status  all` to ensure that all processes have exited
- Install the new RPM package on each machine per your system environment
    - Get the package：[https://github.com/vesoft-inc/nebula/releases/tag/v1.2.0](https://github.com/vesoft-inc/nebula/releases/tag/v1.2.0)
    - Install the package
- Start Nebula
    - Execute `scripts/nebula.service start all` on each machine
    - Execute `scripts/nebula.service status all` to ensure that all processes have started properly

Note: If you are currently using NebulaGraph v1.0.0-RC3 or a previous version, please re-load your data after upgrading to v1.2.0.

Here is the GitHub repo of NebulaGraph: [https://github.com/vesoft-inc/nebula](https://github.com/vesoft-inc/nebula). Please feel free to try the latest version. If you encounter any problem, please ask on our Discussions: [https://github.com/vesoft-inc/nebula/discussions](https://github.com/vesoft-inc/nebula/discussions)

NebulaGraph v1.2.0 has just released. In this version, the `FIND PATH` feature has been enhanced; the `DELETE` function has been optimized. Also, we have fixed some bugs.

NebulaGraph v1.2.0 Release Note

Nebula Graph v2.0.0-beta has just been released! This version supports full-text search and counting the number of nodes and edges within a graph space. Nebula Graph Studio, the graph visualization tool, and Go Importer, the data import tool, are both compatible with Nebula Graph 2.x.

> Note: The compatibility of schema and graph data with Nebula Graph 1.x is still under development.

# Nebula Graph

## Compatible with more nGQL 1.0 queries

- `DESCRIBE TAG/EDGE INDEX` is to obtain information about the index. 
- `REBUILD TAG/EDGE INDEX` is to rebuild an index.
- `SHOW TAG/EDGE INDEXES` is to list the created indexes.
- `SHOW TAG/EDGE INDEXES STATUS` is to return the created index status.

## New features

- Full-text search, allows users to write queries that match terms anywhere within the indexed string properties.
- `LOOKUP ON TAG/EDGE` is to get all vertices of a tag or edges of an edge type.
- `SUBMIT JOB STATS`  & `SHOW STATS` is to get all vertices and edges in the current space.
- Support more openCypher Clauses.
-- Partially supported `MATCH` clause
-- `RETURN`  & `DISTINCT`
-- `LIMIT`  & `SKIP`  
- Add more built-in functions.
-- Predicate functions
-- Scalar functions
-- List functions
-- Aggregating functions
-- Mathematical functions
-- String functions
-- Temporal functions

# Clients

- [CPP Client](https://github.com/vesoft-inc/nebula-clients/tree/master/cpp)

# Nebula Graph Studio

- Compatible with Nebula Graph 2.x，refer to [Studio](https://github.com/vesoft-inc/nebula-web-docker).

# Tools

- Go Importer: Compatible with Nebula Graph 2.x, refer to [Nebula Importer](https://github.com/vesoft-inc/nebula-importer).

# How to Upgrade

Please note that you cannot directly upgrade to Nebula Graph v2.0.0-beta from Nebula Graph 1.x. Follow the steps below to upgrade from v2.0,0-alpha to the beta version:

1. Stop all Nebula services 
    1. Execute scripts/nebula.service stop all on each machine 
    2. Execute scripts/nebula.service status all to confirm all services are stopped
2. Install the new RPM package on each machine according to the OS you are using 
    1. Get package: https://github.com/vesoft-inc/nebula-graph/releases/tag/v2.0.0-beta 
    2. Uninstall the original RPM package `rpm -e nebula-graph-2.0.0-alpha.el6.x86_64.rpm`
    3. Install package: nebula-graph-2.0.0-beta.el6.x86_64.rpm
3. Start Nebula 
    1. Execute scripts/nebula.service start all on each machine 
    2. Execute scripts/nebula.service status all to confirm Nebula services are started on each machine

If you encounter any problem during the upgrade, please feel free to leave your comment below!

Nebula Graph v2.0.0-beta has just been released! This version supports full-text search and counting the number of nodes and edges within a graph space. Nebula Graph Studio, the graph visualization tool, and Go Importer, the data import tool, are both compatible with Nebula Graph 2.x

Nebula Graph v2.0.0-beta Release Note


![NebulaGraph v2.0.0-alpha Release Note](https://user-images.githubusercontent.com/57335825/97855876-4ad18900-1cb0-11eb-909c-3aae112e72a3.png)

# NebulaGraph

> Note: Schema & data are not compatible with 1.0 yet. Still working on the compatibility.

## New Features

* Support String vertex ID
* New data types
  * `NULL` , the property for vertices or edges can be set to  `NULL` .  `NOT NULL`  constraint is supported to ensure the property values are not NULL.
  * Composite types: list, set and map(Cannot be stored as properties).
  * Temporal types like  `DATE`  and  `DATETIME` .
* New Functions
  * `size()`  returns the number of items in a list
  * `time()`  returns the current Time
  * `date()`  or  `datetime()`  Returns the current Date or DateTime
  * `id()`  returns the id of a vertex
  * `tags()`  and  `labels()`  return the tags of the vertex
  * `collect()` , an aggregation function, returns a list containing the values returned by an expression
  * `collect_set()` , aggregation function, returns a set containing the values returned by an expression
  * `properties()`  returns a map containing all the properties of a vertex or an edge
  * `type()`  returns the edge type of an edge
  * `src()`  returns the src id of an edge
  * `dst()`  returns the dst id of an edge
  * `rank()`  returns the rank of an edge
* New Operators
  * `IN`  checks if a specified value matches any value in a list.
  * `CONTAINS`  performs a case-sensitive match regardless of location within a string.
  * `STARTS WITH`  performs a case-sensitive match for the beginning of a string.
  * `ENDS WITH`  performs a case-sensitive match for the ending of a string.
* Explain & Profile.  `EXPLAIN`  displays the execution plan of a nGQL statement without executing the statement. PROFILE executes the statement, then outputs the execution plan as well as the execution profile.
* Subgraph.  `GET SUBGRAPH`  statement retrieves information of vertices and edges reachable from the start vertices over the specified edges to the maximum number of hops.
* Partially supported  `MATCH`  statement.
* A  `DELETE`  statement can have an input from the pipeline  `|` .

## Features different from 1.0

* `CREATE SPACE`  supports specifying the type of vertex ID. The type  `fixed_string` (  `int64`  will be supported in the next release).
* Simplify `UPDATE/UPSERT statement.
* `UPSERT ... SET`  the unspecified properties will be set to the default value when inserting a new vertex/edge. If no default value is set, they will be set to  `NULL` . If the  `NOT NULL`  constraint is set on the property, an error will return.
* `$-`  in the pipeline statement is not equal to  `$-.id`  anymore.
* The expression specified in the default value will be computed when the data inserted instead of schema defined.

## Upcoming Soon (Work in process)

* `DESCRIBE TAG/EDGE INDEX`
* `REBUILD TAG/EDGE INDEX`
* `SHOW TAG/EDGE INDEXES`
* `SHOW TAG/EDGE INDEX STATUS`
* `FETCH PROP ON`  multiple tags
* Compatible with 1.0 Integer vertex ID
* Support more OpenCypher statements
* Backup & Restore
* Fulltext search

# Console

* Nebula-console supports local commands now. For example,  `:set csv`  outputs the query results to the console and the specified CSV file. For more information, please refer to [nebula-console](https://github.com/vesoft-inc/nebula-console).

# Clients

* Java
* Python
* Golang

Clients support connection pooling and load balancing. For more information, please refer to [nebula-clients](https://github.com/vesoft-inc/nebula-clients).

# Studio

* Not Compatible with NebulaGraph 2.0 yet (Working in progress).

# Document

* Please refer to [https://github.com/vesoft-inc/nebula-docs/tree/master/docs-2.0](https://github.com/vesoft-inc/nebula-docs/tree/master/docs-2.0).

If you have any problem or feature request, please leave a comment here: [https://discuss.nebula-graph.io/t/nebula-graph-v2-0-0-alpha-release-note/754](https://discuss.nebula-graph.io/t/nebula-graph-v2-0-0-alpha-release-note/754).


NebulaGraph 2.0.0-alpha has just been released! In this release, nGQL is enhanced; openCypher is gradually supported.