Hadoop external data file path Query

In Hive, appearance is a very important component, which facilitates data sharing.
Because normal tables copy data files to their own directories, you can only save multiple copies of data to share data.
But the appearance solves this problem well.

Create external table sunwg_test09 (ID int, name string)
Row format delimited
Fields terminated by '\ t'
Location '/sunwg/test08 ′;

In fact, the External table can not only specify the HDFS directory, but also the local directory.
For example:
Create external table test10 (ID int, name string)
Row format delimited
Fields terminated by '\ t'
Location 'file: // home/hjl/sunwg /';

There is no directory in the hive. External Store. Warehouse. Dir of the External table. If we create an external table, how can we find the data file? For all the table structures, we have selected the storage method for hive configuration. The most common method is to store them in MySQL.

The configuration snippets in hive-site.xml are as follows:

<Property> <Name> hive. MetaStore. Local </Name> <value> true </value> </property>
<Property> <Name> javax. JDO. Option. connectionurl </Name> <value> JDBC: mysql: // centos1: 3306/hive? Createdatabaseifnotexist = true </value> </property>
<Property> <Name> javax. JDO. Option. connectiondrivername </Name> <value> com. MySQL. JDBC. Driver </value> </property>
<Property> <Name> javax. JDO. Option. connectionusername </Name> <value> hadoop </value> </property>
<Property> <Name> javax. JDO. Option. connectionpassword </Name> <value> hadoop </value> </property>

This section is the storage address, user name, and password of the hive metadata we saved. We can use the mysql client to log on.

Mysql> select * From Tsung where tbl_name = 'sunwg _ test09 ′;
Error 2006 (hy000): MySQL server has gone away
No connection. Trying to reconnect...
Connection ID: 16
Current Database: hjl

+ --- + ----- + --- + ------ + --- + ---- + --- + ------ + ------- +
| Tbl_id | create_time | db_id | last_access_time | Owner | retention | sd_id | tbl_name | tbl_type | view_expanded_text | view_original_text |
+ --- + ----- + --- + ------ + --- + ---- + --- + ------ + ------- +
| 15 | 1299519817 | 1 | 0 | hjl | 0 | 15 | sunwg_test09 | external_table | null |
+ --- + ----- + --- + ------ + --- + ---- + --- + ------ + ------- +
1 row in SET (0.01 Sec)

The table type is external_table.

Mysql> select * from SDS where sd_id = 15;
+ --- + -------------- + ----- + ----------- + ----- + -------------------- + ---- +
| Sd_id | input_format | is_compressed | location | num_buckets | output_format | serde_id |
+ --- + -------------- + ----- + ----------- + ----- + -------------------- + ---- +
| 15 | Org. apache. hadoop. mapred. textinputformat | HDFS: // hadoop00: 9000/hjl/test08 |-1 | Org. apache. hadoop. hive. QL. io. hiveignorekeytextoutputformat | 15 |
+ --- + -------------- + ----- + ----------- + ----- + -------------------- + ---- +
1 row in SET (0.00 Sec)

The data file path of sunwg_test09 in Table SDS is HDFS: // hadoop00: 9000/hjl/test08.