[DRILL-7565] ANALYZE TABLE ... REFRESH METADATA does not work for empty Parquet files

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.17.0
• Fix Version/s: 1.18.0
• Labels: ready-to-commit
• Assignee: Vova Vysotskyi
• Reporter: Bohdan Kazydub
• Reviewer: Bohdan Kazydub
• Created: 03/Feb/20 14:40
• Updated: 21/Feb/20 15:53
• Resolved: 21/Feb/20 15:53

Description

The following query does not create metadata for empty Parquet table:

@Test
  public void testAnalyzeEmptyParquetTable() throws Exception {
    dirTestWatcher.copyResourceToRoot(Paths.get("parquet", "empty"));

    String tableName = "parquet/empty/simple/empty_simple.parquet";

    try {
      client.alterSession(ExecConstants.METASTORE_ENABLED, true);
      testBuilder()
          .sqlQuery("ANALYZE TABLE dfs.`%s` REFRESH METADATA", tableName)
          .unOrdered()
          .baselineColumns("ok", "summary")
          .baselineValues(true, String.format("Collected / refreshed metadata for table [dfs.default.%s]", tableName))
          .go();
    } finally {
      run("analyze table dfs.`%s` drop metadata if exists", tableName);
      client.resetSession(ExecConstants.METASTORE_ENABLED);
    }
  }

but yields

java.lang.AssertionError: Different number of records returned 
Expected :1
Actual   :0
<Click to see difference>


	at org.apache.drill.test.DrillTestWrapper.compareResults(DrillTestWrapper.java:862)
	at org.apache.drill.test.DrillTestWrapper.compareUnorderedResults(DrillTestWrapper.java:567)
	at org.apache.drill.test.DrillTestWrapper.run(DrillTestWrapper.java:171)
	at org.apache.drill.test.TestBuilder.go(TestBuilder.java:145)
	at org.apache.drill.exec.store.parquet.TestEmptyParquet.testSelectWithDisabledMetastore(TestEmptyParquet.java:430)
	at java.lang.Thread.run(Thread.java:748)

When changing expected result set to empty (TestBuilder#expectsEmptyResultSet()), SHOW TABLES command after ANALYZE TABLE ... does not show any table.

Issue Links

• links to: GitHub Pull Request #1985