RMAN backup

[hrishy]

Hi

You are talking two different concepts.

1)TPSIPTR thats for a different purpose all together.

In your question you had asked can i recover a
dropped tablespace the answer is definately
a yes and here is

To recover the database until a specified time, SCN, 
or log sequence number:

After connecting to the target database and, optionally, the recovery catalog database, ensure that the database is mounted. 
If the database is open, shut it down and then mount it: 
SHUTDOWN IMMEDIATE;
STARTUP MOUNT;


Determine the time, SCN, or log sequence that should end recovery. 
For example, if you discover that a user accidentally
dropped a tablespace at 9:02 a.m., 
 then you can recover to 9 a.m.--just before the drop occurred. 
You will lose all changes to the database made after that time. 

You can also examine the alert.log to find the SCN of an event
and recover to a prior SCN. Alternatively, you can determine
the log sequence number that contains the recovery 
termination SCN, and then recover through that log. 
For example, query V$LOG_HISTORY to view the logs that 
you have archived.

RECID      STAMP      THREAD#    SEQUENCE#  FIRST_CHAN FIRST_TIM NEXT_CHANG
---------- ---------- ---------- ---------- ---------- --------- ----------
         1  344890611          1          1      20037 24-SEP-01      20043
         2  344890615          1          2      20043 24-SEP-01      20045
         3  344890618          1          3      20045 24-SEP-01      20046


Perform the following operations within a RUN command: 
Set the end recovery time, SCN, or log sequence. If specifying a time,
 then use the date format specified in the NLS_LANG and
 NLS_DATE_FORMAT environment variables. 
If automatic channels are not configured, then manually
 allocate one or more channels. Restore and recover the database. 
The following example performs an incomplete recovery 
until November 15 at 9 a.m.

RUN
{ 
  SET UNTIL TIME 'Nov 15 2001 09:00:00';
  # SET UNTIL SCN 1000;       # alternatively, you can specify SCN
  # SET UNTIL SEQUENCE 9923;  # alternatively, you can specify log sequence number
  RESTORE DATABASE;
  RECOVER DATABASE;
}


If recovery was successful, then open the database 
and reset the online logs: 
ALTER DATABASE OPEN RESETLOGS;

this is from the documentation.

TPSIPTR is when you want to recover only one
tablespace to a different point in time
you would probably want to use TPSIPTR when
you want to recover a accidentally dropped table.

Hope things clear up a bit :-)

regards
Hrishy