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The
ROWID represents the specific address of a particular row. The ROWID
pseudocolumn is defined with a ROWID datatype.
The ROWID relates to a specific location on a disk drive. Because of this, the
ROWID is the fastest way to retrieve an individual row. However, the ROWID
for a row can change as the result of dumping and reloading the database. For
this reason, we don??™t recommend using the value for the ROWID pseudocolumn
across transaction lines. For example, there is no reason to store a reference
to the ROWID of a row once you??™ve finished using the row in your current
application.
You cannot set the value of the standard ROWID pseudocolumn with any SQL
statement.
The format of the ROWID pseudocolumn changed with Oracle8. Beginning
with Oracle8, the ROWID includes an identifier that points to the database
object number in addition to the identifiers that point to the datafile, block, and
row. You can parse the value returned from the ROWID pseudocolumn to
understand the physical storage of rows in your Oracle database.


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