Multiple choice technology databases

To re-create a database, all existing database files should be reused. The following SQL statement is issued: CREATE DATABASE ABC DATAFILE '/u01/oradata/abc/system0l.dbf' SIZE 100M REUSE LOGFILE GROUP 1 ('/u01/oradata/abc/logla.rdo', '/u02/oradata/abc/loglb.rdo') SIZE 50K REUSE, GROUP 2 ('/u01/oradata/abc/log2a.rdo', '/u02/oradata/abc/log2b.rdo') SIZE 50K REUSE MAXLOGFILES 5 MAXLOGHISTORY 100 MAXDATAFILES 10; Why does the CREATE DATABASE statement fail?

  1. The MAXLOGFILES are set too low

  2. The CONTROLFILE REUSE clause is omitted

  3. The online redo log files cannot be reused

  4. The data file belonging to the SYSTEM tablespace cannot be reused
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The CREATE DATABASE statement fails because CONTROLFILE REUSE clause is missing. When reusing existing database files (specified by REUSE for datafiles and logs), you must explicitly include CONTROLFILE REUSE to allow Oracle to reuse the existing control file. Without this clause, Oracle attempts to create a new control file, causing conflict. Option A is incorrect because MAXLOGFILES=5 is reasonable. Option C is incorrect because online redo logs CAN be reused (the REUSE clause explicitly allows this). Option D is incorrect because the SYSTEM tablespace datafile can be reused with REUSE.

AI explanation

When recreating a database and reusing existing physical files, Oracle also recreates the control file as part of CREATE DATABASE. If the statement doesn't include a CONTROLFILE REUSE clause and a control file already exists at the target location, the command fails because Oracle won't silently overwrite an existing control file without being told to reuse it. The datafile and logfile REUSE clauses shown are fine — it's the missing controlfile clause that causes the failure.

Keep practicing — related questions