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1z0-042 Certification Exam


Today saw Oracle 10g DBA 1Z0-042′s flash back to the database features, the book says to delete a table space can not be completed and used resetlogs recovery, in fact, this mans that if you change the structure of the database, it can not flash back, flashback only logical changes, but I did an experiment.I deleted a table space, and then flash back to the database and found that 1Z0-042 can not open the database, open the database file when prompted datafile 7 offline, the file will be lost if the resetlogs, so I use RMAN to restore, that is, To revert to a previous time, with the UNTIL TIME this syntax, but in the RESTORE to go wrong, and told not restore the control file, at that point in time did not have a backup control file, but the data files have all been restored, in fact, control files recorded SCN SCN is inconsistent with the data file, the database can not be opened, that is, data files than the new control file, and I think the two approaches, one is to rebuild the control file, resetlogs option is to go down in front of a recovery, recovery Before a control file, RMAN’s controlfile autoback I was on, the control files are backed up. I took the second approach.The first is to rebuild the control file with resetlogs option, the new Oracle Certification SCN control file is read from the data file, and then recover database until cancel.The second approach is a cross-resetlogs point in time recovery, because yesterday I had to experiment with resetlogs opened this database, so I restored the control file, also RESET DATABASE to incarnation n, the counterpart of the conversion, or RMAN will reported RMAN-20207 UNTIL TIME is before RESETLOGSS time Cause: UNTIL TIME cannot be less than the database creation time or RESETLOGSS time. Action: Check the UNTIL TIME. If the database needs to be restored to an old incarnation, use the RESET DATABASE TO INCARNATION command. Finally, to recover database, the data is successfully resumed.Frequent use of Oracle Database 10g DBA Certification, you can also find a table in the database before the delete occurred particularly in the form of garbage, generally will not affect the normal use, but when you encounter the following situations to teach you delete it Testinside . 1. The table space 2. If you use Middlegen-Hibernate-r5 friends will find some problems, do not you then as before along with the formation of oracle9 hibernate when the configuration file, the reasons to delete it here no problem. 3. Other cases BINjR8PK5HhrrgMK8KmgQ9nw == This type of table Yes Yes 10g’s new features. Drop Table after table does not actually delete, but “garbage station” in the. You can see below. SQL> SHOW RECYCLEBIN If you want to completely remove, you can use: SQL> PURGE TABLE “BINjR8PK5HhrrgMK8KmgQ9nw ==”; Delete or delete all of this: SQL> PURGE RECYCLEBIN;