[CALCITE-3583] Support serialized to json and deserialized from json for Exchange relation operator

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Duplicate
• Labels: pull-request-available
• Assignee: Unassigned
• Reporter: Wang Yanlin
• Created: 10/Dec/19 07:40
• Updated: 12/Oct/21 09:32
• Resolved: 12/Oct/21 09:32

Description

Currently, serialize Exchange relnode to json will cause exception

// RelWriterTest
@Test public void testExchange() {
    final FrameworkConfig config = RelBuilderTest.config().build();
    final RelBuilder builder = RelBuilder.create(config);
    final RelNode rel = builder
        .scan("EMP")
        .exchange(RelDistributions.hash(ImmutableList.of(0, 1)))
        .build();
    String relJson = RelOptUtil.dumpPlan("", rel,
        SqlExplainFormat.JSON, SqlExplainLevel.EXPPLAN_ATTRIBUTES);
    String s = deserializeAndDumpToTextFormat(getSchema(rel), relJson);
    final String expected = ""
        + "LogicalExchange(distribution=[hash[0, 1]])\n"
        + "  LogicalTableScan(table=[[scott, EMP]])\n";
    assertThat(s, isLinux(expected));
  }

got

java.lang.UnsupportedOperationException: type not serializable: hash[0, 1] (type org.apache.calcite.rel.RelDistributions.RelDistributionImpl)

	at org.apache.calcite.rel.externalize.RelJson.toJson(RelJson.java:290)
	at org.apache.calcite.rel.externalize.RelJsonWriter.put(RelJsonWriter.java:83)
	at org.apache.calcite.rel.externalize.RelJsonWriter.explain_(RelJsonWriter.java:66)
	at org.apache.calcite.rel.externalize.RelJsonWriter.done(RelJsonWriter.java:128)
	at org.apache.calcite.rel.AbstractRelNode.explain(AbstractRelNode.java:299)
	at org.apache.calcite.plan.RelOptUtil.dumpPlan(RelOptUtil.java:1981)
	at org.apache.calcite.plan.RelWriterTest.testExchange(RelWriterTest.java:772)

Issue Links

• relates to: CALCITE-105 Externalize RelNode to and from JSON
• links to: GitHub Pull Request #1642
• links to: GitHub Pull Request #2519