Index pairs的研究

普通B*树的pairs

branch (separator key,dba) paris

leaf (index key,rowid)

 

row#1[8008] flag: -----, lock: 0
col 0; len 2; (2):  c1 03                   --index key
col 1; len 6; (6):  00 40 b9 62 00 01       --rowid

 

通过dbms_utility.data_block_address_file和dbms_utility.data_block_address_block可以得到file#和block#

 

SQL> select to_number('0040b962','xxxxxxxxxxxx') from dual;

TO_NUMBER('0040B962','XXXXXXXXXXXX')
------------------------------------
                             4241762

 

SQL> select dbms_utility.data_block_address_file(4241762),dbms_utility.data_block_address_block(4241762) from dual;

DBMS_UTILITY.DATA_BLOCK_ADDRESS_FILE(4241762)
---------------------------------------------
DBMS_UTILITY.DATA_BLOCK_ADDRESS_BLOCK(4241762)
----------------------------------------------
                                            1
                                         47458

 

 

bitmap index

(key,begin rowid,end rowid,bitmap wrap)

 

row#1[7990] flag: -----, lock: 0
col 0; len 2; (2):  c1 03                    --key
col 1; len 6; (6):  00 40 b9 62 00 00        --begin rowid
col 2; len 6; (6):  00 40 b9 62 00 07        --end rowid
col 3; len 1; (1):  01                       --encoded bitmap(bitmap segment)

其中key和encoded bitmap 储存在所有的bimtap segments中

 

reverse index

和普通index一样，只是值反转

 

row#1[8008] flag: -----, lock: 0
col 0; len 2; (2):  03 c1                    --reverse key
col 1; len 6; (6):  00 40 b9 62 00 01

 

funcation index

 

row#1[8010] flag: -----, lock: 0
col 0; len 1; (1):  42                       --virtual col
col 1; len 6; (6):  00 40 b9 62 00 01        --rowid

 

iot

data储存在index中，所以需要dump主键索引

(key,non_key_column_values)

 

row#0[8022] flag: K----, lock: 0
col 0; len 2; (2):  c1 02                    --primary key
tl: 5 fb: --H-FL-- lb: 0x0  cc: 1
col  0: [ 1]
Dump of memory from 0x0AA86DBB to 0x0AA86DBC
AA86DB0                   61010100                   [...a]  --non_key_column_values
row#1[8012] flag: K----, lock: 0
col 0; len 2; (2):  c1 03
tl: 5 fb: --H-FL-- lb: 0x0  cc: 1
col  0: [ 1]
Dump of memory from 0x0AA86DB1 to 0x0AA86DB2
AA86DB0 00046201                             [.b..]
row#2[8000] flag: K----, lock: 2
col 0; len 2; (2):  c1 04
tl: 7 fb: --H-FL-- lb: 0x0  cc: 1
col  0: [ 3]
Dump of memory from 0x0AA86DA5 to 0x0AA86DA8
AA86DA0          61616103                        [.aaa]

 

 

可以利用dbms_rowid的rowid_relative_fno,rowid_block_number,rowid_object得到file#,block#,obj#