2.4.5　使用describe命令

通过list命令只是查询到了数据库中所有的表名称，但是如果需要表中的详细信息，则需要使用describe命令。

范例如下：

---

    hbase(main):001:0> describe
ERROR: wrong number of arguments (0 for 1)
Here is some help for this command:
Describe the named table. For example:
hbase> describe 't1'
hbase> describe 'ns1:t1'
Alternatively, you can use the abbreviated 'desc' for the same thing.
hbase> desc 't1'
hbase> desc 'ns1:t1'

---

从上述信息可知，我们输入的命令有错误。

正确的操作命令如下：

---

    hbase(main):001:0> describe 'test'
Table test is DISABLED
test
COLUMN FAMILIES DESCRIPTION
{NAME => 'cf2',
BLOOMFILTER => 'ROW',
VERSIONS => '1',
IN_MEMORY => 'false',
KEEP_DELETED_CELLS => 'FALSE',
DATA_BLOCK_ENCODING => 'NONE',
TTL => 'FOREVER',
COMPRESSION => 'NONE',
MIN_VERSIONS =>'0',
BLOCKCACHE => 'true',
BLOCKSIZE => '65536',
REPLICATION_SCOPE => '0'}
{NAME => 'cf1',
BLOOMFILTER => 'ROW',
VERSIONS => '1',
IN_MEMORY => 'false',
KEEP_DELETED_CELLS => 'FALSE',
DATA_BLOCK_ENCODING => 'NONE',
TTL => 'FOREVER',
COMPRESSION => 'NONE',
MIN_VERSIONS =>'0',
BLOCKCACHE => 'true',
BLOCKSIZE => '65536',
REPLICATION_SCOPE => '0'}
2 row(s) in 0.3490 seconds

---

命令解析：查询表名为student的详细信息。需要注意的是，name表示的是列族的名称而不是列的名称。从上面信息中可知，此表student中包含了两个列族，分别是cf1和cf2。