我从Cloudera网站上参考了一个示例，编写了一个自定义的SerDe来解析文件。
http://blog.cloudera.com/blog/2012/12/how-to-use-a-serde-in-apache-hive/
这个示例看起来不错，但是当我使用自定义的Serde创建表格时...
ADD JAR <path-to-hive-serdes-jar>;
CREATE EXTERNAL TABLE tweets (
id BIGINT,
created_at STRING,
source STRING,
favorited BOOLEAN,
retweeted_status STRUCT<
text:STRING,
user:STRUCT<screen_name:STRING,name:STRING>,
retweet_count:INT>,
entities STRUCT<
urls:ARRAY<STRUCT<expanded_url:STRING>>,
user_mentions:ARRAY<STRUCT<screen_name:STRING,name:STRING>>,
hashtags:ARRAY<STRUCT<text:STRING>>>,
text STRING,
user STRUCT<
screen_name:STRING,
name:STRING,
friends_count:INT,
followers_count:INT,
statuses_count:INT,
verified:BOOLEAN,
utc_offset:INT,
time_zone:STRING>,
in_reply_to_screen_name STRING
)
PARTITIONED BY (datehour INT)
ROW FORMAT SERDE 'com.cloudera.hive.serde.JSONSerDe'
LOCATION '/user/flume/tweets';
它执行得非常好，但是当我这样做时
select * from tweets;
我什么都得不到，所以我想知道是否可以在调试模式下运行Hive，以查看它在哪里失败了。