Nebula Graph v2.5.0

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 Lookup statement. #1188
• Supports configuring machine memory watermarks to alleviate OOM issues to some extent. #1067
• Support filter the edges in FindPath statement. #1091
• Support return structure of a graph without properties in Subgraph statement. #1134
• Improve the usage of timestamp function. vesoft-inc/nebula-common#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

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. vesoft-inc/nebula-common#491
• Fixed meta not returning leader change correctly. #423
• Fixed an issue with 'LIMIT', 'ORDER', 'GROUP' statements using variables. #1314
• Fixed issue with db_dump tool printing VID of int type. vesoft-inc/nebula-storage#533
• Fixed the issue that FAILE is still displayed after the Balance task is recovered. vesoft-inc/nebula-storage#528

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

change

• A little bit grammar change of Subgraph

# Add the WITH PROP keyword to the output property
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 versions, there is no need. Example:

Before:
(root@nebula) [basketballplayer]> LOOKUP ON player \
                               ->         YIELD player.age As playerage \
                               ->         | GROUP BY $-.playerage \
                               ->         YIELD $-.playerage as age, count(*) AS number \
                               ->         | ORDER BY number DESC, age DESC;


From v2.5.0
(czp@nebula) [basketballplayer]> LOOKUP ON player \
                               ->         YIELD player.age As playerage \
                               ->         | GROUP BY $-.playerage \
                               ->         YIELD $-.playerage as age, count(*) AS number \
                               ->         | ORDER BY $-.number DESC, $-.age DESC;