[FLINK-16108] StreamSQLExample is failed if running in blink planner

• Type: Bug
• Status: Resolved
• Priority: Critical
• Resolution: Fixed
• Fix Version/s: 1.10.1, 1.11.0
• Component/s: Table SQL / Planner
• Assignee: Jark Wu
• Reporter: Jark Wu
• Created: 17/Feb/20 03:30
• Updated: 25/Dec/20 03:03
• Resolved: 05/Mar/20 11:42

Description

StreamSQLExample in flink-example will fail if the specified planner is blink planner. Exception is as following:

Exception in thread "main" org.apache.flink.table.api.ValidationException: Field types of query result and registered TableSink  do not match.
Query schema: [user: BIGINT, product: STRING, amount: INT]
Sink schema: [amount: INT, product: STRING, user: BIGINT]
	at org.apache.flink.table.planner.sinks.TableSinkUtils$.validateSchemaAndApplyImplicitCast(TableSinkUtils.scala:96)
	at org.apache.flink.table.planner.delegation.PlannerBase.translateToRel(PlannerBase.scala:229)
	at org.apache.flink.table.planner.delegation.PlannerBase$$anonfun$1.apply(PlannerBase.scala:150)
	at org.apache.flink.table.planner.delegation.PlannerBase$$anonfun$1.apply(PlannerBase.scala:150)
	at scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala:234)
	at scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala:234)
	at scala.collection.Iterator$class.foreach(Iterator.scala:891)
	at scala.collection.AbstractIterator.foreach(Iterator.scala:1334)
	at scala.collection.IterableLike$class.foreach(IterableLike.scala:72)
	at scala.collection.AbstractIterable.foreach(Iterable.scala:54)
	at scala.collection.TraversableLike$class.map(TraversableLike.scala:234)
	at scala.collection.AbstractTraversable.map(Traversable.scala:104)
	at org.apache.flink.table.planner.delegation.PlannerBase.translate(PlannerBase.scala:150)
	at org.apache.flink.table.api.java.internal.StreamTableEnvironmentImpl.toDataStream(StreamTableEnvironmentImpl.java:361)
	at org.apache.flink.table.api.java.internal.StreamTableEnvironmentImpl.toAppendStream(StreamTableEnvironmentImpl.java:269)
	at org.apache.flink.table.api.java.internal.StreamTableEnvironmentImpl.toAppendStream(StreamTableEnvironmentImpl.java:260)
	at org.apache.flink.table.examples.java.StreamSQLExample.main(StreamSQLExample.java:90)

Process finished with exit code 1

That's because blink planner will also validate the sink schema even if it is come from toAppendStream(). However, the TableSinkUtils#inferSinkPhysicalDataType should derive sink schema from query schema when the requested type is POJO [1], because fields order of POJO is not deterministic.

[1]: https://github.com/apache/flink/blob/master/flink-table/flink-table-planner-blink/src/main/scala/org/apache/flink/table/planner/sinks/TableSinkUtils.scala#L237

Issue Links

• links to: https://github.com/apache/flink/pull/11236