[SPARK-16628][SQL] Translate file-based relation schema when file schema is inconsistent with catalog schema

sql/hive/src/main/scala/org/apache/spark/sql/hive/orc/OrcFileFormat.scala

@@ -36,7 +36,7 @@ import org.apache.spark.sql.{Row, SparkSession}
 import org.apache.spark.sql.catalyst.InternalRow
 import org.apache.spark.sql.catalyst.expressions._
 import org.apache.spark.sql.execution.datasources._
-import org.apache.spark.sql.hive.{HiveInspectors, HiveShim}
+import org.apache.spark.sql.hive.{HiveInspectors, HiveSessionState, HiveShim}
 import org.apache.spark.sql.sources.{Filter, _}
 import org.apache.spark.sql.types.StructType
 import org.apache.spark.util.SerializableConfiguration
@@ -126,6 +126,9 @@ class OrcFileFormat extends FileFormat with DataSourceRegister with Serializable
     val broadcastedHadoopConf =
       sparkSession.sparkContext.broadcast(new SerializableConfiguration(hadoopConf))
 
+    val convertHiveOrc =
+      sparkSession.sessionState.asInstanceOf[HiveSessionState].convertMetastoreOrc
+
     (file: PartitionedFile) => {
       val conf = broadcastedHadoopConf.value.value
 
@@ -137,7 +140,31 @@ class OrcFileFormat extends FileFormat with DataSourceRegister with Serializable
         Iterator.empty
       } else {
         val physicalSchema = maybePhysicalSchema.get
-        OrcRelation.setRequiredColumns(conf, physicalSchema, requiredSchema)
+
+        // SPARK-16628: an Orc table created by Hive may not store column name correctly in the
+        // Orc files. So the physical schema can mismatch required schema which comes from
+        // metastore schema and reading Orc files will fail.
+        // To fix this, we assume the metastore schema `dataSchema` can match to `physicalSchema`
+        // by each column disregarding the column names. If not, we throw an exception that
+        // suggests users to disable the conversion of Hive Orc tables.
+        val physicalRequiredSchema =
+          if (convertHiveOrc && OrcRelation.isMismatchSchema(physicalSchema, requiredSchema)) {
+            require(physicalSchema.length == dataSchema.length,
+              s"physical schema $physicalSchema in Orc file doesn't match metastore schema " +
+                s"$dataSchema, please disable spark.sql.hive.convertMetastoreOrc to work around " +
+                "this problem.")
+            physicalSchema.fields.zip(dataSchema.fields).map { case (pf, df) =>
+              require(pf.dataType == df.dataType,
+                s"Column $pf in Orc file doesn't match column $df in metastore schema, " +
+                  "please disable spark.sql.hive.convertMetastoreOrc to work around this problem.")
+            }
+            OrcRelation.setRequiredColumns(conf, dataSchema, requiredSchema)
+            StructType(
+              requiredSchema.map(a => dataSchema.fieldIndex(a.name)).map(physicalSchema(_)))
+          } else {
+            OrcRelation.setRequiredColumns(conf, physicalSchema, requiredSchema)
+            requiredSchema
+          }
 
         val orcRecordReader = {
           val job = Job.getInstance(conf)
@@ -161,7 +188,7 @@ class OrcFileFormat extends FileFormat with DataSourceRegister with Serializable
         // Unwraps `OrcStruct`s to `UnsafeRow`s
         OrcRelation.unwrapOrcStructs(
           conf,
-          requiredSchema,
+          physicalRequiredSchema,
           Some(orcRecordReader.getObjectInspector.asInstanceOf[StructObjectInspector]),
           recordsIterator)
       }
@@ -303,6 +330,10 @@ private[orc] object OrcRelation extends HiveInspectors {
     maybeStructOI.map(unwrap).getOrElse(Iterator.empty)
   }
 
+  def isMismatchSchema(physicalSchema: StructType, requestedSchema: StructType): Boolean = {
+    requestedSchema.forall(a => physicalSchema.getFieldIndex(a.name).isEmpty)
+  }
+
   def setRequiredColumns(
       conf: Configuration, physicalSchema: StructType, requestedSchema: StructType): Unit = {
     val ids = requestedSchema.map(a => physicalSchema.fieldIndex(a.name): Integer)

sql/hive/src/test/scala/org/apache/spark/sql/hive/orc/OrcQuerySuite.scala

@@ -590,6 +590,63 @@ class OrcQuerySuite extends QueryTest with BeforeAndAfterAll with OrcTest {
     }
   }
 
+  test("ORC conversion when metastore schema does not match schema stored in ORC files") {
+    withTempView("single") {
+      val singleRowDF = Seq((0, "foo")).toDF("key", "value")
+      singleRowDF.createOrReplaceTempView("single")
+
+      withSQLConf(HiveUtils.CONVERT_METASTORE_ORC.key -> "true") {
+        withTable("dummy_orc") {
+          withTempPath { dir =>
+            val path = dir.getCanonicalPath
+
+            // Create a Metastore ORC table and insert data into it.
+            spark.sql(
+              s"""
+                 |CREATE TABLE dummy_orc(value STRING)
+                 |PARTITIONED BY (key INT)
+                 |STORED AS ORC
+                 |LOCATION '$path'
+               """.stripMargin)
+
+            spark.sql(
+              s"""
+                 |INSERT INTO TABLE dummy_orc
+                 |PARTITION(key=0)
+                 |SELECT value FROM single
+               """.stripMargin)
+
+            val df = spark.sql("SELECT key, value FROM dummy_orc WHERE key=0")
+            checkAnswer(df, singleRowDF)
+
+            // Create a Metastore ORC table with different schema.
+            spark.sql(
+              s"""
+                 |CREATE EXTERNAL TABLE dummy_orc2(value2 STRING)
+                 |PARTITIONED BY (key INT)
+                 |STORED AS ORC
+                 |LOCATION '$path'
+               """.stripMargin)
+
+            spark.sql("ALTER TABLE dummy_orc2 ADD PARTITION(key=0)")
+
+            // The output of the relation is the schema from the Metastore, not the file.
+            val df2 = spark.sql("SELECT key, value2 FROM dummy_orc2 WHERE key=0 AND value2='foo'")
+            checkAnswer(df2, singleRowDF)
+
+            val queryExecution = df2.queryExecution
+            queryExecution.analyzed.collectFirst {
+              case _: LogicalRelation => ()
+            }.getOrElse {
+              fail(s"Expecting the query plan to convert orc to data sources, " +
+                s"but got:\n$queryExecution")
+            }
+          }
+        }
+      }
+    }
+  }
+
   test("Empty schema does not read data from ORC file") {
     val data = Seq((1, 1), (2, 2))
     withOrcFile(data) { path =>