Tips by Burleson
Oracle10g Extended ROWID Format
Rowids of rows that belong to BFTs do not contain the relative
Smallfile Tablespace Rowid Format
Smallfile tablespace has a four-pieces format,
OOOOOOFFFBBBBBBRRR, in which:
- OOOOOO is the data object number of the segment.
- FFF is the tablespace-relative datafile number of the
datafile that contains the row.
- BBBBBB is the data block that contains the row.
- RRR is the slot number identifying the row inside a
Bigfile Tablespace Rowid Format
In a bigfile tablespace, there is only one file that always has
a relative file number of 1024. A bigfile tablespace has a
three-piece format, OOOOOOLLLLLLLLLRRR, in which
- LLLLLLLLL is used to denote the block number. The
concatenation of FFF and BBBBBB makes the encoded block number.
- For BFTs, the only supported way of getting components of
extended rowids is to use the DBMS_ROWID package.
- Here is an example on how to use the dbms_rowid package to
retrieve rowid information:
where rownum < 3;
BIGFILE_ROWID SMALLFILE_ROWID FIRST_NAME LAST_NAME
------------- --------------- -------------------- ---------
1024 4 Ellen Abel
1024 4 Sundar Ande