create
or
replace
package
sys.dbms_rowid
is
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------------
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--? OVERVIEW
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--
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--? This package provides procedures to create ROWIDs and to interpret
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--? their contents
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--? SECURITY
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--
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--? The execution privilege is granted to PUBLIC. Procedures in this
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--? package run under the caller security.
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----------------------------
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----------------------------
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--? ROWID TYPES:
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--
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--?? RESTRICTED - Restricted ROWID
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--
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--?? EXTENDED?? - Extended ROWID
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--
? rowid_type_restricted
constant
integer
:=
0
;
? rowid_type_extended??
constant
integer
:=
1
;
?
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--? ROWID VERIFICATION RESULTS:
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--
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--?? VALID?? - Valid ROWID
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--
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--?? INVALID - Invalid ROWID
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--
? rowid_is_valid??
constant
integer
:=
0
;
? rowid_is_invalid
constant
integer
:=
1
;
?
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--? OBJECT TYPES:
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--
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--?? UNDEFINED - Object Number not defined (for restricted ROWIDs)
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--
? rowid_object_undefined
constant
integer
:=
0
;
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--? ROWID CONVERSION TYPES:
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--
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--?? INTERNAL - convert to/from column of ROWID type
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--
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--?? EXTERNAL - convert to/from string format
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--
? rowid_convert_internal
constant
integer
:=
0
;
? rowid_convert_external
constant
integer
:=
1
;
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--? EXCEPTIONS:
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--
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-- ROWID_INVALID? - invalid rowid format
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--
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-- ROWID_BAD_BLOCK - block is beyond end of file
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--
? ROWID_INVALID
exception
;
????
pragma
exception_init
(ROWID_INVALID, -
1410
);
? ROWID_BAD_BLOCK
exception
;
????
pragma
exception_init
(ROWID_BAD_BLOCK, -
28516
);
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--? PROCEDURES AND FUNCTIONS:
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--
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--
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-- ROWID_CREATE constructs a ROWID from its constituents:
? ??
--這個過程可以用來創建rowid進行比對，但只有oracle自己的rowid才是有效的
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-- rowid_type - type (restricted/extended)
???? -- restricted為0;extended為1
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-- object_number - data object number (rowid_object_undefined for restricted)
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-- relative_fno - relative file number
???? --這是file號
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-- block_number - block number in this file
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-- file_number - file number in this block
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--
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function
rowid_create(rowid_type
IN
number
,
??????????????????????? object_number
IN
number
,
??????????????????????? relative_fno
IN
number
,
?
?????????????????????? block_number
IN
number
,
??????????????????????? row_number
IN
number
)
???????????????????????
return
rowid
;
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pragma
RESTRICT_REFERENCES
(rowid_create,
WNDS
,
RNDS
,
WNPS
,
RNPS
);
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--
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-- ROWID_INFO breaks ROWID into its components and returns them:
? ??
--這個過程幾乎就是ROWID_CREATE的逆過程，返回所有屬性
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-- rowid_in - ROWID to be interpreted
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-- rowid_type - type (restricted/extended)
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-- object_number - data object number (rowid_object_undefined for restricted)
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-- relative_fno - relative file number
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-- block_number - block number in this file
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-- file_number - file number in this block
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-- ts_type_in - type of tablespace which this row belongs to
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--????????????? 'BIGFILE' indicates Bigfile Tablespace
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--? ??????????? 'SMALLFILE' indicates Smallfile (traditional pre-10i) TS.
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--????????????? NOTE: These two are the only allowed values for this param
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--
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procedure
rowid_info( rowid_in
IN
rowid
,
??????????????????????? rowid_type
OUT
number
,
?????????????
????????? object_number
OUT
number
,
??????????????????????? relative_fno
OUT
number
,
??????????????????????? block_number
OUT
number
,
??????????????????????? row_number
OUT
number
,
??????????????????????? ts_type_in
IN
varchar2
default
'SMALLFILE'
);
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pragma
RESTRICT_REFERENCES
(rowid_info,
WNDS
,
RNDS
,
WNPS
,
RNPS
);
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--
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-- ROWID_TYPE returns the type of a ROWID (restricted/extended_nopart,..)
? ??
--restricted則返回0;extended則返回1
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-- row_id - ROWID to be interpreted
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--
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function
rowid_type(row_id
IN
rowid
)
???????????????????????
return
number
;
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pragma
RESTRICT_REFERENCES
(rowid_type,
WNDS
,
RNDS
,
WNPS
,
RNPS
);
?
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--
?
-- ROWID_OBJECT extracts the data object number from a ROWID.
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-- ROWID_OBJECT_UNDEFINED is returned for restricted rowids.
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--
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-- row_id - ROWID to be interpreted
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--
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function
rowid_object(row_id
IN
rowid
)
???????????????????????
return
number
;
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pragma
RESTRICT_REFERENCES
(rowid_object,
WNDS
,
RNDS
,
WNPS
,
RNPS
);
?
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--
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-- ROWID_RELATIVE_FNO extracts the relative file number from a ROWID.
? ??
--返回對應的datafile號，這個還是還是有點用處的，因為同一張表不一定屬于同一datafile
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-- row_id - ROWID to be interpreted
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-- ts_type_in - type of tablespace which this row belongs to
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--
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function
rowid_relative_fno(row_id
IN
rowid
,
????????????????????????????? ts_type_in
IN
varchar2
default
'SMALLFILE'
)
???????????????????????
return
number
;
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pragma
RESTRICT_REFERENCES
(rowid_relative_fno,
WNDS
,
RNDS
,
WNPS
,
RNPS
);
?
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--
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-- ROWID_BLOCK_NUMBER extracts the block number from a ROWID.
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--
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-- row_id - ROWID to be interpreted
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-- ts_type_in - type of tablespace which this row belongs to
? ??
-- ts_type_in只有2種選擇，'SMALLFILE'和'BIGFILE'
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--
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function
rowid_block_number(row_id
IN
rowid
,
????????????????????????????? ts_type_in
IN
varchar2
default
'SMALLFILE'
)
???????????????????????
return
number
;
?
pragma
RESTRICT_REFERENCES
(rowid_block_number,
WNDS
,
RNDS
,
WNPS
,
RNPS
);
?
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--
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-- ROWID_ROW_NUMBER extracts the row number from a ROWID.
? ??
--這個函數返回該條記錄在block中的相對位置，大小不一定的，也不一定連續(如果刪除過數據)
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-- row_id - ROWID to be interpreted
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--
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function
rowid_row_number(row_id
IN
rowid
)
???????????????????????
return
number
;
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pragma
RESTRICT_REFERENCES
(rowid_row_number,
WNDS
,
RNDS
,
WNPS
,
RNPS
);
?
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--
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-- ROWID_TO_ABSOLUTE_FNO extracts the relative file number from a ROWID,
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-- which addresses a row in a given table
? ??
--用于標注準確文件號，多用于分區表
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-- row_id - ROWID to be interpreted
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--
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-- schema_name - name of the schema which contains the table
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--
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-- object_name - table name
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--
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function
rowid_to_absolute_fno(row_id
IN
rowid
,
???????????????????????????????? schema_name
IN
varchar2
,
???????????????????????????????? object_name
IN
varchar2
)
???????????????????????
return
number
;
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pragma
RESTRICT_REFERENCES
(rowid_to_absolute_fno,
WNDS
,
WNPS
,
RNPS
);
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--
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-- ROWID_TO_EXTENDED translates the restricted ROWID which addresses
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-- a row in a given table to the extended format. Later, it may be removed
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-- from this package into a different place
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--
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-- old_rowid - ROWID to be converted
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--
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-- schema_name - name of the schema which contains the table (OPTIONAL)
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--
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-- object_name - table name (OPTIONAL)
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--
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-- conversion_type - rowid_convert_internal/external_convert_external
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--?????????????????? (whether old_rowid was stored in a column of ROWID
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--??????????????????? type, or the character string)
? ??
--rowid_convert_internal (:=0)
???? --rowid_convert_external (:=1)
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function
rowid_to_extended(old_rowid
IN
rowid
,
???????????????????????????? schema_name
IN
varchar2
,
????????????????????
??????? object_name
IN
varchar2
,
???????????????????????????? conversion_type
IN
integer
)
???????????????????????
return
rowid
;
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pragma
RESTRICT_REFERENCES
(rowid_to_extended,
WNDS
,
WNPS
,
RNPS
);
?
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--
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-- ROWID_TO_RESTRICTED translates the extnded ROWID into a restricted format
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--
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-- old_rowid - ROWID to be converted
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--
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-- conversion_type - internal/external (IN)
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--
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-- conversion_type - rowid_convert_internal/external_convert_external
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--?????????????????? (whether returned rowid will be stored in a column of
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--??????????????????? ROWID type, or the character string)
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--
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function
rowid_to_restricted(old_rowid
IN
rowid
,
?????????????????????????????? conversion_type
IN
integer
)
???????????????????????
return
rowid
;
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pragma
RESTRICT_REFERENCES
(rowid_to_restricted,
WNDS
,
RNDS
,
WNPS
,
RNPS
);
?
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--
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-- ROWID_VERIFY verifies the ROWID. It returns rowid_valid or rowid_invalid
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-- value depending on whether a given ROWID is valid or not.
? ??
--這個函數是用于檢驗是否可以講rowid從restricted改為extended的
???? --可以修改則返回0;不可以則返回1
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-- rowid_in - ROWID to be verified
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--
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-- schema_name - name of the schema which contains the table
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--
?
-- object_name - table name
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--
?
-- conversion_type - rowid_convert_internal/external_convert_external
?
--?????????????????? (whether old_rowid was stored in a column of ROWID
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--??????????????????? type, or the character string)
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--
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function
rowid_verify(rowid_in
IN
rowid
,
??????????????????????? schema_name
IN
varchar2
,
??????????????????????? object_name
IN
varchar2
,
??????????????????????? conversion_type
IN
integer
)
???????????????????????
return
number
;
?
pragma
RESTRICT_REFERENCES
(rowid_verify,
WNDS
,
WNPS
,
RNPS
);
?
end
;
***************************************************************************************
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?
??? 總結一下：
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??? 1、ROWID_CREATE：輸入相應信息后自己創建一個ROWID并返回，主要用于測試比對
??? 2、ROWID_INFO：返回ROWID確定的各種信息
??? 3、ROWID_TYPE：返回ROWID類型(restricted or extended)
??? 4、ROWID_OBJECT：返回該ROWID對應的OBJECT的OBJ#
??? 5、ROWID_RELATIVE_FNO：返回該ROWID對應的對應文件號
??? 6、ROWID_BLOCK_NUMBER：返回該ROWID所在的BLOCK號
??? 7、ROWID_ROW_NUMBER：返回該行數據在BLOCK中的相對位置
??? 8、ROWID_TO_ABSOLUTE_FNO：返回相關的完全數據文件號
??? 9、ROWID_TO_EXTENDED：將restricted類型的ROWID修改為extended
??? 10、ROWID_TO_RESTRICTED：將extended類型的ROWID修改為restricted
??? 11、ROWID_VERIFY：查看是否可以對ROWID的類型進行修改
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??? 這個包的應用也比較簡單，沒什么可說的了，再轉個eygle的文章，也是比較簡單的應用的：
??? -----------------------
???
http://www.eygle.com/archives/2004/12/dbms_rowid_get_rowid_detail.html
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