Add a config flag tpcds.use-varchar-type in Presto - Java TPC-DS Connector

presto-docs/src/main/sphinx/connector/tpcds.rst

@@ -66,4 +66,6 @@ Property Name                                      Description
 ================================================== ========================================================================== ==============================
 ``tpcds.splits-per-node``                          Number of data splits generated per Presto worker node when querying       Number of available processors
                                                    data from the TPCDS connector.
+
+``tpcds.use-varchar-type``                         Toggle all char columns to varchar in the TPC-DS connector.                false
 ================================================== ========================================================================== ==============================

presto-tpcds/src/main/java/com/facebook/presto/tpcds/TpcdsConnectorFactory.java

@@ -64,6 +64,7 @@ public ConnectorHandleResolver getHandleResolver()
     public Connector create(String catalogName, Map<String, String> config, ConnectorContext context)
     {
         int splitsPerNode = getSplitsPerNode(config);
+        boolean useVarcharType = useVarcharType(config);
         NodeManager nodeManager = context.getNodeManager();
         return new Connector()
         {
@@ -76,7 +77,7 @@ public ConnectorTransactionHandle beginTransaction(IsolationLevel isolationLevel
             @Override
             public ConnectorMetadata getMetadata(ConnectorTransactionHandle transactionHandle)
             {
-                return new TpcdsMetadata();
+                return new TpcdsMetadata(useVarcharType);
             }
 
             @Override
@@ -109,6 +110,16 @@ private int getSplitsPerNode(Map<String, String> properties)
         }
     }
 
+    private boolean useVarcharType(Map<String, String> properties)
+    {
+        try {
+            return parseBoolean(firstNonNull(properties.get("tpcds.use-varchar-type"), String.valueOf(false)));
+        }
+        catch (NumberFormatException e) {
+            throw new IllegalArgumentException("Invalid property tpcds.use-varchar-type");
+        }
+    }
+
     private boolean isWithNoSexism(Map<String, String> properties)
     {
         return parseBoolean(firstNonNull(properties.get("tpcds.with-no-sexism"), String.valueOf(false)));

presto-tpcds/src/main/java/com/facebook/presto/tpcds/TpcdsMetadata.java

@@ -64,13 +64,16 @@ public class TpcdsMetadata
     private final Set<String> tableNames;
     private final TpcdsTableStatisticsFactory tpcdsTableStatisticsFactory = new TpcdsTableStatisticsFactory();
 
-    public TpcdsMetadata()
+    private final boolean useVarcharType;
+
+    public TpcdsMetadata(boolean useVarcharType)
     {
         ImmutableSet.Builder<String> tableNames = ImmutableSet.builder();
         for (Table tpcdsTable : Table.getBaseTables()) {
             tableNames.add(tpcdsTable.getName().toLowerCase(ENGLISH));
         }
         this.tableNames = tableNames.build();
+        this.useVarcharType = useVarcharType;
     }
 
     @Override
@@ -134,14 +137,14 @@ public ConnectorTableMetadata getTableMetadata(ConnectorSession session, Connect
         Table table = Table.getTable(tpcdsTableHandle.getTableName());
         String schemaName = scaleFactorSchemaName(tpcdsTableHandle.getScaleFactor());
 
-        return getTableMetadata(schemaName, table);
+        return getTableMetadata(schemaName, table, useVarcharType);
     }
 
-    private static ConnectorTableMetadata getTableMetadata(String schemaName, Table tpcdsTable)
+    private static ConnectorTableMetadata getTableMetadata(String schemaName, Table tpcdsTable, boolean useVarcharType)
     {
         ImmutableList.Builder<ColumnMetadata> columns = ImmutableList.builder();
         for (Column column : tpcdsTable.getColumns()) {
-            columns.add(new ColumnMetadata(column.getName(), getPrestoType(column.getType())));
+            columns.add(new ColumnMetadata(column.getName(), getPrestoType(column.getType(), useVarcharType)));
         }
         SchemaTableName tableName = new SchemaTableName(schemaName, tpcdsTable.getName());
         return new ConnectorTableMetadata(tableName, columns.build());
@@ -189,7 +192,7 @@ public Map<SchemaTableName, List<ColumnMetadata>> listTableColumns(ConnectorSess
         for (String schemaName : getSchemaNames(session, Optional.ofNullable(prefix.getSchemaName()))) {
             for (Table tpcdsTable : Table.getBaseTables()) {
                 if (prefix.getTableName() == null || tpcdsTable.getName().equals(prefix.getTableName())) {
-                    ConnectorTableMetadata tableMetadata = getTableMetadata(schemaName, tpcdsTable);
+                    ConnectorTableMetadata tableMetadata = getTableMetadata(schemaName, tpcdsTable, useVarcharType);
                     tableColumns.put(new SchemaTableName(schemaName, tpcdsTable.getName()), tableMetadata.getColumns());
                 }
             }
@@ -243,7 +246,7 @@ public static double schemaNameToScaleFactor(String schemaName)
         }
     }
 
-    public static Type getPrestoType(ColumnType tpcdsType)
+    public static Type getPrestoType(ColumnType tpcdsType, boolean useVarcharType)
     {
         switch (tpcdsType.getBase()) {
             case IDENTIFIER:
@@ -255,6 +258,9 @@ public static Type getPrestoType(ColumnType tpcdsType)
             case DECIMAL:
                 return createDecimalType(tpcdsType.getPrecision().get(), tpcdsType.getScale().get());
             case CHAR:
+                if (useVarcharType) {
+                    return createVarcharType(tpcdsType.getPrecision().get());
+                }
                 return createCharType(tpcdsType.getPrecision().get());
             case VARCHAR:
                 return createVarcharType(tpcdsType.getPrecision().get());

presto-tpcds/src/main/java/com/facebook/presto/tpcds/TpcdsRecordSet.java

@@ -57,7 +57,10 @@ public TpcdsRecordSet(Results results, List<Column> columns)
         this.columns = ImmutableList.copyOf(columns);
         ImmutableList.Builder<Type> columnTypes = ImmutableList.builder();
         for (Column column : columns) {
-            columnTypes.add(getPrestoType(column.getType()));
+            // The TPCDS config tpcds.use-varchar-type is set to true only for native execution, since char type is
+            // currently unsupported in Presto native. This function is only used by the Presto java TPCDS connector
+            // so the argument useVarcharType is false here.
+            columnTypes.add(getPrestoType(column.getType(), false));
         }
         this.columnTypes = columnTypes.build();
     }
@@ -103,7 +106,7 @@ public long getReadTimeNanos()
         @Override
         public Type getType(int field)
         {
-            return getPrestoType(columns.get(field).getType());
+            return getPrestoType(columns.get(field).getType(), false);
         }
 
         @Override

presto-tpcds/src/test/java/com/facebook/presto/tpcds/TestTpcdsMetadataStatistics.java

@@ -45,7 +45,7 @@ public class TestTpcdsMetadataStatistics
 {
     private static final EstimateAssertion estimateAssertion = new EstimateAssertion(0.01);
     private static final ConnectorSession session = null;
-    private final TpcdsMetadata metadata = new TpcdsMetadata();
+    private final TpcdsMetadata metadata = new TpcdsMetadata(false);
 
     @Test
     public void testNoTableStatsForNotSupportedSchema()