[CALCITE-4177] RelJson should throw if asked to deserialize a call to an unknown operator

• Type: Improvement
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Fix Version/s: 1.28.0
• Labels: pull-request-available
• Assignee: Wang Yanlin
• Reporter: Wang Yanlin
• Created: 14/Aug/20 09:42
• Updated: 20/Oct/21 05:24
• Resolved: 20/Sep/21 06:12

Description

Currently, when deserialize a RexNode fails, calcite returns a null value, causing NPE in somewhere else. So we cannot get any information about the SqlOperator in the stacktrace.  This makes it hard to determine the reason when deserialize a very long json string.

Caused by: java.lang.NullPointerException
	at java.util.Objects.requireNonNull(Objects.java:203)
	at org.apache.calcite.rel.core.AggregateCall.<init>(AggregateCall.java:98)
	at org.apache.calcite.rel.core.AggregateCall.create(AggregateCall.java:198)
	at org.apache.calcite.rel.externalize.RelJsonReader.toAggCall(RelJsonReader.java:289)
	at org.apache.calcite.rel.externalize.RelJsonReader.access$500(RelJsonReader.java:59)
	at org.apache.calcite.rel.externalize.RelJsonReader$2.getAggregateCalls(RelJsonReader.java:172)
	at org.apache.calcite.rel.core.Aggregate.<init>(Aggregate.java:220)
	at org.apache.calcite.rel.logical.LogicalAggregate.<init>(LogicalAggregate.java:105)
	at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
	at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
	at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
	at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
	at org.apache.calcite.rel.externalize.RelJsonReader.readRel(RelJsonReader.java:264)
	at org.apache.calcite.rel.externalize.RelJsonReader.readRels(RelJsonReader.java:91)
	at org.apache.calcite.rel.externalize.RelJsonReader.read(RelJsonReader.java:85)
	at org.apache.calcite.plan.RelWriterTest.lambda$deserializeAndDumpToTextFormat$6(RelWriterTest.java:894)
	at org.apache.calcite.tools.Frameworks.lambda$withPlanner$0(Frameworks.java:131)
	at org.apache.calcite.prepare.CalcitePrepareImpl.perform(CalcitePrepareImpl.java:914)
	at org.apache.calcite.tools.Frameworks.withPrepare(Frameworks.java:180)
	... 67 more

Maybe it's better to throw exception instead of return null, adding the name, kind, and syntax in the error message

Issue Links

• is fixed by: CALCITE-4199 Add nullability annotations to the methods and fields, ensure consistency with checkerframework
• links to: GitHub Pull Request #2110
• links to: GitHub Pull Request #2520