[ https://issues.apache.org/jira/browse/SPARK-27424?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Dongjoon Hyun updated SPARK-27424: ---------------------------------- Affects Version/s: (was: 3.0.0) 3.1.0 > Joining of one stream against the most recent update in another stream > ---------------------------------------------------------------------- > > Key: SPARK-27424 > URL: https://issues.apache.org/jira/browse/SPARK-27424 > Project: Spark > Issue Type: Improvement > Components: Structured Streaming > Affects Versions: 3.1.0 > Reporter: Thilo Schneider > Priority: Major > Attachments: join-last-update-design.pdf > > > Currently, adding the most recent update of a row with a given key to another > stream is not possible. This situation arises if one wants to use the current > state, of one object, for example when joining the room temperature with the > current weather. > This ticket covers creation of a {{stream_lead}} and modification of the > streaming join logic (and state store) to additionally allow joins of the > form > {code:sql} > SELECT * > FROM A, B > WHERE > A.key = B.key > AND A.time >= B.time > AND A.time < stream_lead(B.time) > {code} > The major aspect of this change is that we actually need a third watermark to > cover how late updates may come. > A rough sketch may be found in the attached document. -- This message was sent by Atlassian Jira (v8.3.4#803005) --------------------------------------------------------------------- To unsubscribe, e-mail: issues-unsubscr...@spark.apache.org For additional commands, e-mail: issues-h...@spark.apache.org