Nebula Graph 2.5.0 release notes¶

Feature¶

• Support management of session. #280
• Support terminate the slow queries, know issue: there is a delay in querying and terminating the query due to the implementation. #1152
• Enhance the ability to extract the indices from expressions for the LOOKUP statement. #1188
• Supports configuring machine memory watermarks to alleviate OOM issues to some extent. 1067
• Support filter the edges in the FindPath statement. #1091
• Support return structure of a graph without properties in the Subgraph statement.#1134
• Improve the usage of the timestamp function. #515
• Support for querying the version of each service. #944
• Index and TTL can be supported together. #382
• Support the creation of full-text indexes on specified properties. #460
• Support make comment when create space or schema. #895
• Support for full-text index rebuild. #1123

Enhancement¶

• The Listener interface is optimized to support full data acquisition. #465, #484
• The leader table of the meta is reorganized. #439
• Add a DiskManager to check disk capacity. #461
• Improve heartbeat of raft to avoid leader change. #438
• Support concurrently go/fetch/lookup in storage. #503
• Enhanced for the EXISTS function to the MAP. #973
• Enforce the use of aggregate functions, such as COUNT(v)+AVG(v). #968

Bug fix¶

• Fixed multiple statement execution problems caused by permissions. #1165
• Fixed unwinding causing no results. #1018
• Fixed crash problems caused by aggregation functions in some scenarios. #1015
• Fixed index matching problems with OR expressions. #1005
• Fixed case sensitivity of functions. #927
• Fixed issue where query index creation information was not checked for Tag/Edge type. #933
• Fixed a bug in the Substring function. #491
• Fixed meta not returning leader change correctly. #423
• Fixed an issue with LIMIT, ORDER, GROUP statements using variables. #1314
• Fixed issue with the db_dump tool printing VID of the int type. #533
• Fixed the issue that FAILE is still displayed after the Balance task is recovered. #528

Changes & Known issues¶

• A little bit grammar change of Subgraph.

  # Add the WITH PROP keyword to the output property in 2.5.0.
  GET SUBGRAPH WITH PROP FROM <vids>
  
  # The original syntax will only output the graph structure without properties.
  GET SUBGRAPH FROM <vids>#
  

• We must use the symbol $-. in ORDER BY. But in earlier releases, there is no need.

  # We must use the symbol `$-.` in `ORDER BY` in 2.5.0.
  nebula> LOOKUP ON player \
          YIELD player.age As playerage \
          | GROUP BY $-.playerage \
          YIELD $-.playerage as age, count(*) AS number \
          | ORDER BY $-.number DESC, $-.age DESC;
  
  # There is no need to use the symbol `$-.` in earlier releases.
  nebula> LOOKUP ON player \
          YIELD player.age As playerage \
          | GROUP BY $-.playerage \
          YIELD $-.playerage as age, count(*) AS number \
          | ORDER BY number DESC, age DESC;
  

For the known bug/issue in 2.5.0, see issues.