Shulou(Shulou.com)06/01 Report--

One. Official illustration

This figure involves three versions of the avatar Incarnation.

Incarnation 1:

The lowest black horizontal line starts from SCN1 and goes through SCN1000 to SCN2000, which is the first incarnation of the database, called Incarnation 1, which then becomes the current incarnation (current incarnation).

Incarnation 2:

Suppose in avatar 1, we perform a point-in-time recovery (incomplete recovery), and the specified place is the location of SCN1000, and then we open the database by using the Resetlogs option, and avatar 2 appears (tilting the solid black line 45 °), and avatar 2 starts with SCN1000 and continues to SCN3000. At this point, we call avatar 1 the parent avatar of avatar 2 (parent incarnation), and avatar 2 becomes the current avatar (current incarnation).

Incarnation 3:

Let's take a look at the solid black line tilted 45 °to the upper right corner, which is the avatar 2. In Avatar 2, it starts with SCN1000, goes through SCN2000, and continues to SCN3000. Suppose that in Avatar 2, we perform a point-in-time recovery (incomplete recovery), and the specified place is the location of SCN2000, and then the database is opened through the Resetlogs option, Avatar 3 appears (at the highest black horizontal line), and Avatar 3 starts with SCN2000 and continues to the SCN3000 of the black horizontal line. At this time, we call avatar 2 the parent avatar of avatar 3, avatar 1 is the ancestor incarnation of avatar 3, and avatar 3 becomes the current incarnation (current incarnation).

Two. Scene simulation

Scene simulation:

(1)

(2) due to the deletion of Table A, it needs to be restored to SCN1046437, when Open resetlogs is opened and a new avatar incarnation 2 is opened. Table An is recovered, but Table B and Table C are lost.

(3) if you want to continue to restore to the time of creating Table C, you need to specify avatar 1 (reset database to incarnation 1), and then perform restore + recover implementation to restore to the time of creating Table C. at this time, Open resetlogs opens and opens a new avatar incarnation 3. At this time, Avatar 2 becomes an orphan avatar (ORPHAN). The current situation is Table B, Table C exists, Table An is lost.

(4) to return to avatar 2 again, you need to specify avatar 2 (reset database to incarnation 2), and then perform restore+recover implementation to restore to avatar 2. At this time, you need to open Open resetlogs and open a new avatar 4. At this time, avatar 3 becomes an orphan avatar (ORPHAN), and avatar 2 becomes a parent avatar (Parent).

Three. Orphan backup test:

/ / current avatar 4, make a cold backup

/ / restore to avatar 3, open avatar 5, and use the cold backup of avatar 4 for recovery test when the data file of avatar 5 is damaged.

/ / open reported an error

/ / recover reported an error

/ / trace reconstruction control file error

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