[SPARK-26188][SQL] FileIndex: don't infer data types of partition columns if user specifies schema

sql/core/src/main/scala/org/apache/spark/sql/execution/datasources/PartitioningAwareFileIndex.scala

@@ -126,33 +126,15 @@ abstract class PartitioningAwareFileIndex(
     val caseInsensitiveOptions = CaseInsensitiveMap(parameters)
     val timeZoneId = caseInsensitiveOptions.get(DateTimeUtils.TIMEZONE_OPTION)
       .getOrElse(sparkSession.sessionState.conf.sessionLocalTimeZone)
-    val inferredPartitionSpec = PartitioningUtils.parsePartitions(
+
+    val caseSensitive = sparkSession.sqlContext.conf.caseSensitiveAnalysis
+    PartitioningUtils.parsePartitions(
       leafDirs,
       typeInference = sparkSession.sessionState.conf.partitionColumnTypeInferenceEnabled,
       basePaths = basePaths,
+      userSpecifiedSchema = userSpecifiedSchema,
+      caseSensitive = caseSensitive,
       timeZoneId = timeZoneId)
-    userSpecifiedSchema match {
-      case Some(userProvidedSchema) if userProvidedSchema.nonEmpty =>
-        val userPartitionSchema =
-          combineInferredAndUserSpecifiedPartitionSchema(inferredPartitionSpec)
-
-        // we need to cast into the data type that user specified.
-        def castPartitionValuesToUserSchema(row: InternalRow) = {
-          InternalRow((0 until row.numFields).map { i =>
-            val dt = inferredPartitionSpec.partitionColumns.fields(i).dataType
-            Cast(
-              Literal.create(row.get(i, dt), dt),
-              userPartitionSchema.fields(i).dataType,
-              Option(timeZoneId)).eval()
-          }: _*)
-        }
-
-        PartitionSpec(userPartitionSchema, inferredPartitionSpec.partitions.map { part =>
-          part.copy(values = castPartitionValuesToUserSchema(part.values))
-        })
-      case _ =>
-        inferredPartitionSpec
-    }
   }
 
   private def prunePartitions(

sql/core/src/main/scala/org/apache/spark/sql/execution/datasources/PartitioningUtils.scala

@@ -31,7 +31,7 @@ import org.apache.spark.sql.catalyst.InternalRow
 import org.apache.spark.sql.catalyst.analysis.{Resolver, TypeCoercion}
 import org.apache.spark.sql.catalyst.catalog.CatalogTypes.TablePartitionSpec
 import org.apache.spark.sql.catalyst.expressions.{Attribute, Cast, Literal}
-import org.apache.spark.sql.catalyst.util.DateTimeUtils
+import org.apache.spark.sql.catalyst.util.{CaseInsensitiveMap, DateTimeUtils}
 import org.apache.spark.sql.types._
 import org.apache.spark.sql.util.SchemaUtils
 
@@ -94,18 +94,34 @@ object PartitioningUtils {
       paths: Seq[Path],
       typeInference: Boolean,
       basePaths: Set[Path],
+      userSpecifiedSchema: Option[StructType],
+      caseSensitive: Boolean,
       timeZoneId: String): PartitionSpec = {
-    parsePartitions(paths, typeInference, basePaths, DateTimeUtils.getTimeZone(timeZoneId))
+    parsePartitions(paths, typeInference, basePaths, userSpecifiedSchema,
+      caseSensitive, DateTimeUtils.getTimeZone(timeZoneId))
   }
 
   private[datasources] def parsePartitions(
       paths: Seq[Path],
       typeInference: Boolean,
       basePaths: Set[Path],
+      userSpecifiedSchema: Option[StructType],
+      caseSensitive: Boolean,
       timeZone: TimeZone): PartitionSpec = {
+    val userSpecifiedDataTypes = if (userSpecifiedSchema.isDefined) {
+      val nameToDataType = userSpecifiedSchema.get.fields.map(f => f.name -> f.dataType).toMap
+      if (caseSensitive) {
+        CaseInsensitiveMap(nameToDataType)
+      } else {
+        nameToDataType
+      }
+    } else {
+      Map.empty[String, DataType]
+    }
+
     // First, we need to parse every partition's path and see if we can find partition values.
     val (partitionValues, optDiscoveredBasePaths) = paths.map { path =>
-      parsePartition(path, typeInference, basePaths, timeZone)
+      parsePartition(path, typeInference, basePaths, userSpecifiedDataTypes, timeZone)
     }.unzip
 
     // We create pairs of (path -> path's partition value) here
@@ -147,14 +163,22 @@ object PartitioningUtils {
         columnNames.zip(literals).map { case (name, Literal(_, dataType)) =>
           // We always assume partition columns are nullable since we've no idea whether null values
           // will be appended in the future.
-          StructField(name, dataType, nullable = true)
+          StructField(name, userSpecifiedDataTypes.getOrElse(name, dataType), nullable = true)
         }
       }
 
       // Finally, we create `Partition`s based on paths and resolved partition values.
       val partitions = resolvedPartitionValues.zip(pathsWithPartitionValues).map {
-        case (PartitionValues(_, literals), (path, _)) =>
-          PartitionPath(InternalRow.fromSeq(literals.map(_.value)), path)
+        case (PartitionValues(columnNames, literals), (path, _)) =>
+          val values = columnNames.zip(literals).map {
+            case (name, literal) =>
+              if (userSpecifiedDataTypes.contains(name)) {
+                Cast(literal, userSpecifiedDataTypes(name), Option(timeZone.getID)).eval()
+              } else {
+                literal.value
+              }
+          }
+          PartitionPath(InternalRow.fromSeq(values), path)
       }
 
       PartitionSpec(StructType(fields), partitions)
@@ -185,6 +209,7 @@ object PartitioningUtils {
       path: Path,
       typeInference: Boolean,
       basePaths: Set[Path],
+      userSpecifiedDataTypes: Map[String, DataType],
       timeZone: TimeZone): (Option[PartitionValues], Option[Path]) = {
     val columns = ArrayBuffer.empty[(String, Literal)]
     // Old Hadoop versions don't have `Path.isRoot`
@@ -206,7 +231,7 @@ object PartitioningUtils {
         // Let's say currentPath is a path of "/table/a=1/", currentPath.getName will give us a=1.
         // Once we get the string, we try to parse it and find the partition column and value.
         val maybeColumn =
-          parsePartitionColumn(currentPath.getName, typeInference, timeZone)
+          parsePartitionColumn(currentPath.getName, typeInference, userSpecifiedDataTypes, timeZone)
         maybeColumn.foreach(columns += _)
 
         // Now, we determine if we should stop.
@@ -239,6 +264,7 @@ object PartitioningUtils {
   private def parsePartitionColumn(
       columnSpec: String,
       typeInference: Boolean,
+      userSpecifiedDataTypes: Map[String, DataType],
       timeZone: TimeZone): Option[(String, Literal)] = {
     val equalSignIndex = columnSpec.indexOf('=')
     if (equalSignIndex == -1) {
@@ -250,7 +276,13 @@ object PartitioningUtils {
       val rawColumnValue = columnSpec.drop(equalSignIndex + 1)
       assert(rawColumnValue.nonEmpty, s"Empty partition column value in '$columnSpec'")
 
-      val literal = inferPartitionColumnValue(rawColumnValue, typeInference, timeZone)
+      val literal = if (userSpecifiedDataTypes.contains(columnName)) {
+        // SPARK-26188: if user provides corresponding column schema, process the column as String
+        //              type and cast it as user specified data type later.
+        inferPartitionColumnValue(rawColumnValue, false, timeZone)
+      } else {
+        inferPartitionColumnValue(rawColumnValue, typeInference, timeZone)
+      }
       Some(columnName -> literal)
     }
   }

sql/core/src/test/scala/org/apache/spark/sql/execution/datasources/FileIndexSuite.scala

@@ -30,6 +30,7 @@ import org.apache.spark.sql.catalyst.util._
 import org.apache.spark.sql.functions.col
 import org.apache.spark.sql.internal.SQLConf
 import org.apache.spark.sql.test.SharedSQLContext
+import org.apache.spark.sql.types.{StringType, StructField, StructType}
 import org.apache.spark.util.{KnownSizeEstimation, SizeEstimator}
 
 class FileIndexSuite extends SharedSQLContext {
@@ -49,6 +50,21 @@ class FileIndexSuite extends SharedSQLContext {
     }
   }
 
+  test("SPARK-26188: don't infer data types of partition columns if user specifies schema") {
+    withTempDir { dir =>
+      val partitionDirectory = new File(dir, s"a=4d")
+      partitionDirectory.mkdir()
+      val file = new File(partitionDirectory, "text.txt")
+      stringToFile(file, "text")
+      val path = new Path(dir.getCanonicalPath)
+      val schema = StructType(Seq(StructField("a", StringType, false)))
+      val fileIndex = new InMemoryFileIndex(spark, Seq(path), Map.empty, Some(schema))
+      val partitionValues = fileIndex.partitionSpec().partitions.map(_.values)
+      assert(partitionValues.length == 1 && partitionValues(0).numFields == 1 &&
+        partitionValues(0).getString(0) == "4d")
+    }
+  }
+
   test("InMemoryFileIndex: input paths are converted to qualified paths") {
     withTempDir { dir =>
       val file = new File(dir, "text.txt")

sql/core/src/test/scala/org/apache/spark/sql/execution/datasources/parquet/ParquetPartitionDiscoverySuite.scala

@@ -101,7 +101,7 @@ class ParquetPartitionDiscoverySuite extends QueryTest with ParquetTest with Sha
       "hdfs://host:9000/path/a=10.5/b=hello")
 
     var exception = intercept[AssertionError] {
-      parsePartitions(paths.map(new Path(_)), true, Set.empty[Path], timeZoneId)
+      parsePartitions(paths.map(new Path(_)), true, Set.empty[Path], None, true, timeZoneId)
     }
     assert(exception.getMessage().contains("Conflicting directory structures detected"))
 
@@ -115,6 +115,8 @@ class ParquetPartitionDiscoverySuite extends QueryTest with ParquetTest with Sha
       paths.map(new Path(_)),
       true,
       Set(new Path("hdfs://host:9000/path/")),
+      None,
+      true,
       timeZoneId)
 
     // Valid
@@ -128,6 +130,8 @@ class ParquetPartitionDiscoverySuite extends QueryTest with ParquetTest with Sha
       paths.map(new Path(_)),
       true,
       Set(new Path("hdfs://host:9000/path/something=true/table")),
+      None,
+      true,
       timeZoneId)
 
     // Valid
@@ -141,6 +145,8 @@ class ParquetPartitionDiscoverySuite extends QueryTest with ParquetTest with Sha
       paths.map(new Path(_)),
       true,
       Set(new Path("hdfs://host:9000/path/table=true")),
+      None,
+      true,
       timeZoneId)
 
     // Invalid
@@ -154,6 +160,8 @@ class ParquetPartitionDiscoverySuite extends QueryTest with ParquetTest with Sha
         paths.map(new Path(_)),
         true,
         Set(new Path("hdfs://host:9000/path/")),
+        None,
+        true,
         timeZoneId)
     }
     assert(exception.getMessage().contains("Conflicting directory structures detected"))
@@ -174,20 +182,22 @@ class ParquetPartitionDiscoverySuite extends QueryTest with ParquetTest with Sha
         paths.map(new Path(_)),
         true,
         Set(new Path("hdfs://host:9000/tmp/tables/")),
+        None,
+        true,
         timeZoneId)
     }
     assert(exception.getMessage().contains("Conflicting directory structures detected"))
   }
 
   test("parse partition") {
     def check(path: String, expected: Option[PartitionValues]): Unit = {
-      val actual = parsePartition(new Path(path), true, Set.empty[Path], timeZone)._1
+      val actual = parsePartition(new Path(path), true, Set.empty[Path], Map.empty, timeZone)._1
       assert(expected === actual)
     }
 
     def checkThrows[T <: Throwable: Manifest](path: String, expected: String): Unit = {
       val message = intercept[T] {
-        parsePartition(new Path(path), true, Set.empty[Path], timeZone)
+        parsePartition(new Path(path), true, Set.empty[Path], Map.empty, timeZone)
       }.getMessage
 
       assert(message.contains(expected))
@@ -231,6 +241,7 @@ class ParquetPartitionDiscoverySuite extends QueryTest with ParquetTest with Sha
       path = new Path("file://path/a=10"),
       typeInference = true,
       basePaths = Set(new Path("file://path/a=10")),
+      Map.empty,
       timeZone = timeZone)._1
 
     assert(partitionSpec1.isEmpty)
@@ -240,6 +251,7 @@ class ParquetPartitionDiscoverySuite extends QueryTest with ParquetTest with Sha
       path = new Path("file://path/a=10"),
       typeInference = true,
       basePaths = Set(new Path("file://path")),
+      Map.empty,
       timeZone = timeZone)._1
 
     assert(partitionSpec2 ==
@@ -258,6 +270,8 @@ class ParquetPartitionDiscoverySuite extends QueryTest with ParquetTest with Sha
           paths.map(new Path(_)),
           true,
           rootPaths,
+          None,
+          true,
           timeZoneId)
       assert(actualSpec.partitionColumns === spec.partitionColumns)
       assert(actualSpec.partitions.length === spec.partitions.length)
@@ -370,7 +384,7 @@ class ParquetPartitionDiscoverySuite extends QueryTest with ParquetTest with Sha
   test("parse partitions with type inference disabled") {
     def check(paths: Seq[String], spec: PartitionSpec): Unit = {
       val actualSpec =
-        parsePartitions(paths.map(new Path(_)), false, Set.empty[Path], timeZoneId)
+        parsePartitions(paths.map(new Path(_)), false, Set.empty[Path], None, true, timeZoneId)
       assert(actualSpec === spec)
     }