// lookup the columns
Map<String, ColumnHandle> allColumnHandles = metadata.getColumnHandles(tableHandle);
ImmutableList.Builder<ColumnHandle> columnHandlesBuilder = ImmutableList.builder();
ImmutableList.Builder<Type> columnTypesBuilder = ImmutableList.builder();
for (String columnName : columnNames) {
ColumnHandle columnHandle = allColumnHandles.get(columnName);
checkArgument(columnHandle != null, "Table %s does not have a column %s", tableName, columnName);
columnHandlesBuilder.add(columnHandle);
ColumnMetadata columnMetadata = metadata.getColumnMetadata(tableHandle, columnHandle);
columnTypesBuilder.add(columnMetadata.getType());
}