Restore tablespace USERS doesn't work. Oracle backup - oracle

Question

I created a schema and my_table_test;
ALTER SESSION SET CURRENT_SCHEMA=c##wojtek_admin;
CREATE TABLE my_table_test
( id_test INT
);
Then I created a backup using: BACKUP TABLESPACE USERS FORMAT 'c:\FRA\users%u';
Then I dropped my_table_test and run below commands:
RMAN> RUN{
2> SQL 'ALTER TABLESPACE USERS OFFLINE';
3> RESTORE TABLESPACE USERS;
4> RECOVER TABLESPACE USERS;
5> SQL 'ALTER TABLESPACE USERS ONLINE';
6> }
Why my_table_test is dropped after I restored USERS TABLESPACE?

Answer 1

In a multitenant database you will have several 'USERS' tablespaces. One at the CDB level and one for each PDB.
RMAN> report schema;
Report of database schema for database with db_unique_name T101N
List of Permanent Datafiles
===========================
File Size(MB) Tablespace RB segs Datafile Name
---- -------- -------------------- ------- ------------------------
1 960 SYSTEM YES +DATAC4/T101N/DATAFILE/system.500.1057688607
3 620 SYSAUX NO +DATAC4/T101N/DATAFILE/sysaux.498.1057688643
4 840 UNDOTBS1 YES +DATAC4/T101N/DATAFILE/undotbs1.587.1057688657
5 310 PDB$SEED:SYSTEM NO +DATAC4/T101N/86B637B62FE07A65E053F706E80A27CA/DATAFILE/system.482.1057689319
6 380 PDB$SEED:SYSAUX NO +DATAC4/T101N/86B637B62FE07A65E053F706E80A27CA/DATAFILE/sysaux.503.1057689319
7 5 USERS NO +DATAC4/T101N/DATAFILE/users.499.1057688659
8 190 PDB$SEED:UNDOTBS1 NO +DATAC4/T101N/86B637B62FE07A65E053F706E80A27CA/DATAFILE/undotbs1.489.1057689319
9 310 PDB1:SYSTEM YES +DATAC4/T101N/B52F60948095635FE053B506330A63CA/DATAFILE/system.405.1057690077
10 390 PDB1:SYSAUX NO +DATAC4/T101N/B52F60948095635FE053B506330A63CA/DATAFILE/sysaux.501.1057690077
11 195 PDB1:UNDOTBS1 YES +DATAC4/T101N/B52F60948095635FE053B506330A63CA/DATAFILE/undotbs1.497.1057690077
12 5 PDB1:USERS NO +DATAC4/T101N/B52F60948095635FE053B506330A63CA/DATAFILE/users.566.1057690091
List of Temporary Files
=======================
File Size(MB) Tablespace Maxsize(MB) Tempfile Name
---- -------- -------------------- ----------- --------------------
1 67 TEMP 32767 +DATAC4/T101N/TEMPFILE/temp.573.1057688719
2 43 PDB$SEED:TEMP 32767 +DATAC4/T101N/B52F34797E9D6750E053B506330AE7C0/TEMPFILE/temp.481.1057689337
3 43 PDB1:TEMP 32767 +DATAC4/T101N/B52F60948095635FE053B506330A63CA/TEMPFILE/temp.496.1057690079
Note! RMAN's best feature. RMAN can actually tell you what to do in different scenarios.
# data recovery advisor (DRA)
list failure all;
advise failure;
repair failure preview;
repair failure;

Answer 2

First, it's important to note that it looks like you're using a Multitenant Database but you've decided to put user data inside the root container, this is generally a bad idea - you should be using a Pluggable Database for pretty much everything (this will also mean you don't need to prefix your usernames with C##.
Your restore and recover statements will recover the tablespace up until now. If you want to recover it to before you dropped the tablespace then Oracle will also need to do some work on the system tablespace (for the data dictionary) - but you don't only want to restore and recover your USERS tablespace. You'd need to restore your backup somewhere else, recover it to the desired point, then take the USERS tablespace and put it back into your original database.
This is simply referred to as Tablespace Point In Time Recovery, Oracle has helpfully done all the hard scripting work for you, but you should read what's going on https://docs.oracle.com/cd/E11882_01/backup.112/e10642/rcmtspit.htm#BRADV89790
RECOVER TABLESPACE users
UNTIL ?
AUXILIARY DESTINATION '?';
(Once you've read the docs you'll see how to fill this out).
There is also the ability to do this easily at a table level, so if you want to only recover that dropped table and not revert everything else in that tablespace, you could:
RECOVER TABLE c##wojtek_admin.my_table_test
UNTIL ?
AUXILIARY DESTINATION '?' ;
See https://oracle-base.com/articles/12c/rman-table-point-in-time-recovery-12cr1 for further details.