There are a few restrictions on bitmap join indexes:
Only one of the tables in the bitmap join index can be updated concurrently by different
transactions when the bitmap join index is being used.
No table can appear more than once in the join.
Bitmap join indexes cannot be created on an IOT or a temporary table.
A bitmap join index cannot be created with the UNIQUE attribute.
The join column(s) used for the index must be the primary key or have a unique
constraint in the table being joined to the table with the bitmap index.
Oracle Data Pump
Oracle Data Pump, new to Oracle 10g, provides similar functionality to the original export (exp)
and import (imp) utilities, but the infrastructure for Data Pump Export and Import is more servercentric.
In fact, the original exp and imp utilities should only be used if you must import a dump
set from a previous version of Oracle into an Oracle 10g database, or if you must export a dump
set from an Oracle 10g database to be imported into a previous version of Oracle. I gave a brief
introduction to Oracle Data Pump in Chapter 11 from the perspective of data recovery; I??™ll
elaborate on the features of Data Pump in this chapter from a VLDB perspective.
The new command-line clients, expdp and impdp, use DBMS_METADATA to extract the
object definitions from the data dictionary as XML or DDL or use DBMS_DATAPUMP to perform
the transfer of both metadata and data from one database to another.
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