Examples with VirtualColumns org.apache.druid.segment.VirtualColumns used on opensource projects

Example 21 with VirtualColumns

use of org.apache.druid.segment.VirtualColumns in project druid by druid-io.

the class VirtualColumnsTest method testGetColumnCapabilitiesWithFallbackDoubleBase.

@Test
public void testGetColumnCapabilitiesWithFallbackDoubleBase() {
    final VirtualColumns virtualColumns = makeVirtualColumns();
    final ColumnInspector baseInspector = column -> {
        if (REAL_COLUMN_NAME.equals(column)) {
            return ColumnCapabilitiesImpl.createSimpleNumericColumnCapabilities(ColumnType.DOUBLE);
        } else {
            return null;
        }
    };
    Assert.assertEquals(ValueType.FLOAT, virtualColumns.getColumnCapabilitiesWithFallback(baseInspector, "expr").getType());
    Assert.assertEquals(ValueType.DOUBLE, virtualColumns.getColumnCapabilitiesWithFallback(baseInspector, "expr2").getType());
    Assert.assertEquals(ValueType.DOUBLE, virtualColumns.getColumnCapabilitiesWithFallback(baseInspector, REAL_COLUMN_NAME).getType());
}

Example 22 with VirtualColumns

use of org.apache.druid.segment.VirtualColumns in project hive by apache.

the class DruidStorageHandlerUtils method extractColName.

@Nullable
public static String extractColName(ExprNodeDesc expr, List<VirtualColumn> virtualColumns) {
    if (!druidSupportedTypeInfos.contains(expr.getTypeInfo())) {
        // We cannot pass the bloom filter to druid since bloom filter tests for exact object bytes.
        return null;
    }
    if (expr instanceof ExprNodeColumnDesc) {
        return ((ExprNodeColumnDesc) expr).getColumn();
    }
    ExprNodeGenericFuncDesc funcDesc = null;
    if (expr instanceof ExprNodeGenericFuncDesc) {
        funcDesc = (ExprNodeGenericFuncDesc) expr;
    }
    if (null == funcDesc) {
        return null;
    }
    GenericUDF udf = funcDesc.getGenericUDF();
    // bail out if its not a simple cast expression.
    if (funcDesc.getChildren().size() == 1 && funcDesc.getChildren().get(0) instanceof ExprNodeColumnDesc) {
        return null;
    }
    String columnName = ((ExprNodeColumnDesc) (funcDesc.getChildren().get(0))).getColumn();
    ValueType targetType = null;
    if (udf instanceof GenericUDFBridge) {
        Class<? extends UDF> udfClass = ((GenericUDFBridge) udf).getUdfClass();
        if (udfClass.equals(UDFToDouble.class)) {
            targetType = ValueType.DOUBLE;
        } else if (udfClass.equals(UDFToFloat.class)) {
            targetType = ValueType.FLOAT;
        } else if (udfClass.equals(UDFToLong.class)) {
            targetType = ValueType.LONG;
        }
    } else if (udf instanceof GenericUDFToString) {
        targetType = ValueType.STRING;
    }
    if (targetType == null) {
        return null;
    }
    String virtualColumnExpr = DruidQuery.format("CAST(%s, '%s')", columnName, targetType.toString());
    for (VirtualColumn column : virtualColumns) {
        if (column instanceof ExpressionVirtualColumn && ((ExpressionVirtualColumn) column).getExpression().equals(virtualColumnExpr)) {
            // Found an existing virtual column with same expression, no need to add another virtual column
            return column.getOutputName();
        }
    }
    Set<String> usedColumnNames = virtualColumns.stream().map(col -> col.getOutputName()).collect(Collectors.toSet());
    final String name = SqlValidatorUtil.uniquify("vc", usedColumnNames, SqlValidatorUtil.EXPR_SUGGESTER);
    ExpressionVirtualColumn expressionVirtualColumn = new ExpressionVirtualColumn(name, virtualColumnExpr, targetType, ExprMacroTable.nil());
    virtualColumns.add(expressionVirtualColumn);
    return name;
}