猪铸造/数据类型

Question

我试图转储到相关文件AVRO但我得到一个奇怪的错误：

org.apache.pig.data.DataByteArray cannot be cast to java.lang.CharSequence 

我不使用DataByteArray（字节阵列），参见下面的关系的描述。

sensitiveSet: {rank_ID: long,name: chararray,customerId: long,VIN: chararray,birth_date: chararray,fuel_mileage: chararray,fuel_consumption: chararray} 

即使我不明确铸造我得到了同样的错误：

sensitiveSet = foreach sensitiveSet generate (long) $0, (chararray) $1, (long) $2, (chararray) $3, (chararray) $4, (chararray) $5, (chararray) $6; 

STORE sensitiveSet INTO 'testOut2222.avro' 
USING org.apache.pig.piggybank.storage.avro.AvroStorage('no_schema_check', 'schema', '{"type":"record","name":"xxxx","namespace":"","fields":[{"name":"rank_ID","type":"long"},{"name":"name","type":"string","store":"no","sensitive":"na"},{"name":"customerId","type":"string","store":"yes","sensitive":"yes"},{"name":"VIN","type":"string","store":"yes","sensitive":"yes"},{"name":"birth_date","type":"string","store":"yes","sensitive":"no"},{"name":"fuel_mileage","type":"string","store":"yes","sensitive":"no"},{"name":"fuel_consumption","type":"string","store":"yes","sensitive":"no"}]}'); 

编辑：

我试图确定哪些应该是包含另外两个一个元组的输出模式元组，即stats:tuple(c:tuple(),d:tuple)。

下面的代码不能像预期的那样工作。它以某种方式产生结构为：

stats:tuple(b:tuple(c:tuple(),d:tuple())) 

以下是由describe产生的输出。

sourceData: {com.mortardata.pig.dataspliter_36: (stats: ((name: chararray,customerId: chararray,VIN: chararray,birth_date: chararray,fuel_mileage: chararray,fuel_consumption: chararray),(name: chararray,customerId: chararray,VIN: chararray,birth_date: chararray,fuel_mileage: chararray,fuel_consumption: chararray)))} 

是否有可能创建如下结构，这意味着我需要从前面的示例中删除元组b。

grunt> describe sourceData; 
sourceData: {t: (s: (name: chararray,customerId: chararray,VIN: chararray,birth_date: chararray,fuel_mileage: chararray,fuel_consumption: chararray),n: (name: chararray,customerId: chararray,VIN: chararray,birth_date: chararray,fuel_mileage: chararray,fuel_consumption: chararray))} 

下面的代码不能按预期工作。

public Schema outputSchema(Schema input) { 
    Schema sensTuple = new Schema(); 
    sensTuple.add(new Schema.FieldSchema("name", DataType.CHARARRAY)); 
    sensTuple.add(new Schema.FieldSchema("customerId", DataType.CHARARRAY)); 
    sensTuple.add(new Schema.FieldSchema("VIN", DataType.CHARARRAY)); 
    sensTuple.add(new Schema.FieldSchema("birth_date", DataType.CHARARRAY)); 
    sensTuple.add(new Schema.FieldSchema("fuel_mileage", DataType.CHARARRAY)); 
    sensTuple.add(new Schema.FieldSchema("fuel_consumption", DataType.CHARARRAY)); 

    Schema nonSensTuple = new Schema(); 
    nonSensTuple.add(new Schema.FieldSchema("name", DataType.CHARARRAY)); 
    nonSensTuple.add(new Schema.FieldSchema("customerId", DataType.CHARARRAY)); 
    nonSensTuple.add(new Schema.FieldSchema("VIN", DataType.CHARARRAY)); 
    nonSensTuple.add(new Schema.FieldSchema("birth_date", DataType.CHARARRAY)); 
    nonSensTuple.add(new Schema.FieldSchema("fuel_mileage", DataType.CHARARRAY)); 
    nonSensTuple.add(new Schema.FieldSchema("fuel_consumption", DataType.CHARARRAY)); 


    Schema parentTuple = new Schema(); 
    parentTuple.add(new Schema.FieldSchema(null, sensTuple, DataType.TUPLE)); 
    parentTuple.add(new Schema.FieldSchema(null, nonSensTuple, DataType.TUPLE)); 


    Schema outputSchema = new Schema(); 
    outputSchema.add(new Schema.FieldSchema("stats", parentTuple, DataType.TUPLE)); 

    return new Schema(new Schema.FieldSchema(getSchemaName(this.getClass().getName().toLowerCase(), input), outputSchema, DataType.TUPLE)); 

的UDF的exec方法返回：

public Tuple exec(Tuple tuple) throws IOException {  
    Tuple parentTuple = mTupleFactory.newTuple(); 
    parentTuple.append(tuple1); 
    parentTuple.append(tuple2); 

EDIT2（固定）

... 
Schema outputSchema = new Schema(); 
outputSchema.add(new Schema.FieldSchema("stats", parentTuple, DataType.TUPLE)); 

回报新模式（新Schema.FieldSchema（getSchemaName（this.getClass（）.getName （）.toLowerCase（），input），outputSchema，DataType.TUPLE）;

return outputSchema; 

现在我回来从UDF正确的架构，所有的项目都是chararray但是当我尝试存储这些物品放入Avro的文件类型：字符串，我得到了同样的错误：

java.lang.Exception: org.apache.avro.file.DataFileWriter$AppendWriteException: java.lang.ClassCastException: org.apache.pig.data.DataByteArray cannot be cast to java.lang.CharSequence 
     at org.apache.hadoop.mapred.LocalJobRunner$Job.runTasks(LocalJobRunner.java:462) 
     at org.apache.hadoop.mapred.LocalJobRunner$Job.run(LocalJobRunner.java:522) 

解决： 确定，问题在于数据并没有被转换为UDF正文中的正确类型 - exec（）方法。看起来现在起作用了！

Answer 1

通常这意味着您正在使用不保留模式的UDF或某处丢失的UDF。我相信DataByteArray是真实类型未知时的后备类型。您可能需要添加种族来解决此问题，但更好的解决方案是修复任何UDF放弃架构。