silence created FLINK-23723: ------------------------------- Summary: Look up join support PROCTIME() function Key: FLINK-23723 URL: https://issues.apache.org/jira/browse/FLINK-23723 Project: Flink Issue Type: Improvement Components: Table SQL / API Reporter: silence
Now,when we what to use look up join we must declare procetime attribute on source table. this is relatively troublesome, and in some complex scenarios(eg. Top-N) , look up join cannot be performed because of the loss of processtime attribute. Moreover, in the process of look up join, the processing time is of no practical use. can we support specifying `PROCTIME()` directly in the join without declaring it in the source table, like: {code:sql} SELECT o.order_id, o.total, c.country, c.zip FROM Orders AS o JOIN Customers FOR SYSTEM_TIME AS OF PROCTIME() AS c ON o.customer_id = c.id; {code} Now it throws an exception {code:java} Caused by: java.lang.AssertionError: Temporal table can only be used in temporal join and only supports 'FOR SYSTEM_TIME AS OF' left table's time attribute field. Querying a temporal table using 'FOR SYSTEM TIME AS OF' syntax with an expression call 'PROCTIME()' is not supported yet. at org.apache.calcite.util.Litmus$1.fail(Litmus.java:31) at org.apache.flink.table.planner.plan.nodes.logical.FlinkLogicalSnapshot.isValid(FlinkLogicalSnapshot.scala:60) {code} -- This message was sent by Atlassian Jira (v8.3.4#803005)