Hbase 使用方法

HBase 0.20 + Hadoop 0.20

回課程大綱

列出所有 table

hbase(main):>	list

新增 table

A . 直接增加一個表 t2

hbase(main):>	create 't2'

B . 增加一個擁有 'f1','f2','fn' 為 column family 的表: t1

hbase(main):>	create 't1','f1','f2','fn'   

查詢 Table 欄位

hbase(main):> describe 't1'

執行結果參考

hbase(main):> describe 't1'
DESCRIPTION                                                             ENABLED                               
 {NAME => 't1', FAMILIES => [{NAME => 'f1', COMPRESSION => 'NONE', VERS true                                  
 IONS => '3', TTL => '2147483647', BLOCKSIZE => '65536', IN_MEMORY => '                                       
 false', BLOCKCACHE => 'true'}, {NAME => 'f2', COMPRESSION => 'NONE', V                                       
 ERSIONS => '3', TTL => '2147483647', BLOCKSIZE => '65536', IN_MEMORY =                                       
 > 'false', BLOCKCACHE => 'true'}, {NAME => 'fn', COMPRESSION => 'NONE'                                       
 , VERSIONS => '3', TTL => '2147483647', BLOCKSIZE => '65536', IN_MEMOR                                       
 Y => 'false', BLOCKCACHE => 'true'}]} 

加入cell-value

需先擁有表 t1 與column-family : f1 並且加入一個 column-quantifier c1

hbase(main):>	put 't1', 'r1', 'f1', 'v1'    
hbase(main):>	put 't1', 'r1', 'f1:c1', 'v2'    
hbase(main):>	put 't1', 'r2', 'f2', 'v3'
hbase(main):>	put 't1', 'r2', 'f2:c2', 'v4'

Table: 't1'
row-key	'f1'		'f2'		'fn'	column-family
	*	'c1'	*	'c2'	*	column-quantifier
r1	v1
		v2
r2			v3
				v4

列出cell-value

A . 列出一列(row)

hbase(main):>	get 't1', 'r1'

執行結果參考

COLUMN                    CELL                
 f1:                         timestamp=1285737082689, value=v1                                                
 f1:c1                       timestamp=1285737085874, value=v2                                          

Table: 't1'
row-key	'f1'		'f2'		'fn'	column-family
	*	'c1'	*	'c2'	*	column-quantifier
r1	v1
		v2
r2			v3
				v4

B . 列出一個 cell 的值

hbase(main):>   get 't1', 'r1', {COLUMN => 'f1:c1'}

執行結果參考

COLUMN                       CELL                             
 f1:c1                       timestamp=1285737085874, value=v2

Table: 't1'
row-key	'f1'		'f2'		'fn'	column-family
	*	'c1'	*	'c2'	*	column-quantifier
r1	v1
		v2
r2			v3
				v4

刪除 cell-value

hbase(main):>	deleteall 't1','r1'

執行結果：會把 row-key 是 'r1' 的所有紀錄。此時資料表 't1' 會變成如下表所示。

hbase(main):> scan 't1'                 
ROW    COLUMN+CELL                                                                      
 r2    column=f2:, timestamp=1285737091644, value=v3                                    
 r2    column=f2:c2, timestamp=1285737094157, value=v4

Table: 't1'
row-key	'f1'		'f2'		'fn'	column-family
	*	'c1'	*	'c2'	*	column-quantifier
r2			v3
				v4

加入column family

hbase(main):>	disable 't1'
hbase(main):>   alter 't1', {NAME => 'f3'}
hbase(main):>   enable 't1'

執行結果：多了一個 column-family 'f3' 可以用 describe 指令查詢，結果示意如下表：

hbase(main):021:0> describe 't1'
DESCRIPTION                                                             ENABLED                               
 {NAME => 't1', FAMILIES => [{NAME => 'f1', COMPRESSION => 'NONE', VERS true                                  
 IONS => '3', TTL => '2147483647', BLOCKSIZE => '65536', IN_MEMORY => '                                       
 false', BLOCKCACHE => 'true'}, {NAME => 'f2', COMPRESSION => 'NONE', V                                       
 ERSIONS => '3', TTL => '2147483647', BLOCKSIZE => '65536', IN_MEMORY =                                       
 > 'false', BLOCKCACHE => 'true'}, {NAME => 'f3', VERSIONS => '3', COMP                                       
 RESSION => 'NONE', TTL => '2147483647', BLOCKSIZE => '65536', IN_MEMOR                                       
 Y => 'false', BLOCKCACHE => 'true'}, {NAME => 'fn', COMPRESSION => 'NO                                       
 NE', VERSIONS => '3', TTL => '2147483647', BLOCKSIZE => '65536', IN_ME                                       
 MORY => 'false', BLOCKCACHE => 'true'}]}

Table: 't1'
row-key	'f1'		'f2'		'f3'	'fn'	column-family
	*	'c1'	*	'c2'	*	*	column-quantifier
r2			v3
				v4

刪除column family

hbase(main):>	disable 't1'
hbase(main):>	alter 't1', {NAME => 'f1', METHOD => 'delete'}
hbase(main):>   enable 't1'

執行結果：會移除 column family 為 'f1' 的所有欄位，可用 describe 指令確認，結果如下表所示。

hbase(main):053:0> describe 't1'
DESCRIPTION                                                             ENABLED                               
 {NAME => 't1', FAMILIES => [{NAME => 'f2', COMPRESSION => 'NONE', VERS true                                  
 IONS => '3', TTL => '2147483647', BLOCKSIZE => '65536', IN_MEMORY => '                                       
 false', BLOCKCACHE => 'true'}, {NAME => 'f3', COMPRESSION => 'NONE', V                                       
 ERSIONS => '3', TTL => '2147483647', BLOCKSIZE => '65536', IN_MEMORY =                                       
 > 'false', BLOCKCACHE => 'true'}, {NAME => 'fn', COMPRESSION => 'NONE'                                       
 , VERSIONS => '3', TTL => '2147483647', BLOCKSIZE => '65536', IN_MEMOR                                       
 Y => 'false', BLOCKCACHE => 'true'}]}                                                                        
1 row(s) in 0.0200 seconds

Table: 't1'
row-key		'f2'		'f3'	'fn'	column-family
		*	'c2'	*	*	column-quantifier
r2		v3
			v4

節點狀態

hbase(main):>	status

刪除整張table

hbase(main):>	truncate 't1'

• 執行完 truncate 後，所有 't1' 的內容都會被移除。但此時，下 list 還會有 't1' 這個表格存在。

hbase(main):>	disable 't1'
hbase(main):>	drop 't1'

• 要完整移除 't1' 資料表，必須使用 disable 先將 't1' 停用，再用 drop 指令把 't1' 完全刪除。