Techniques to create physically and transactionally consistent copies of
one or more database objects without impacting the availability of the
target database objects are described. In one technique, a consistent
copy is created as of the time a copy utility is executed. In another
technique, a consistent copy is created as of an arbitrary specified
time. This approach modifies a prior copy to bring it "up-to-date." In
yet another technique, a consistent copy is created by starting with a
current snapshot of the target database objects and selectively removing
updates from it back to a user specified arbitrary point-in-time. Each of
the described techniques generate consistent copies of the target
database objects without blocking users from accessing the target objects
during the copy operation.