Understanding Flashback Technology - OCP: Oracle Database 12c Administrator Certified Professional - page 367

By specifying the system-assigned object name in your Flashback Drop , you avoid
duplicate-name issues and ensure that only the specific table that you've selected (and the
specific version of that table) will be restored.
Flashback Drop functionality offers a simple way to recover from logical corruption caused
when a table has been dropped in error. It is simple, fast, and works well. But there are other
types of logical corruption that you must also be able to deal with, and those will require dif-
ferent tools. In the next section, we will introduce you to the next one: Flashback Query.

Regarding the Behavior of Dependent Objects after Undropping

When you recover a table from the Recycle Bin, the triggers, constraints, and indexes are
also brought back; however, the names of the dependent objects remain as they were in the
Recycle Bin. For example, if table T has an index IN_T , a primary key constraint PK_T , and a
trigger named TR_T and the table is dropped and later flashed back, all of these dependent
objects will revert back to table T but with different names:

SQL> select trigger_name from user_triggers where table_name = 'T';
TRIGGER_NAME
------------------------------
BIN$VJSEhlG2cMngQA4KH2h7+A==$0
SQL> select index_name from user_indexes where table_name = 'T';
INDEX_NAME
------------------------------
BIN$VJSEhlG0cMngQA4KH2h7+A==$0
BIN$VJSEhlG1cMngQA4KH2h7+A==$0
SQL> select constraint_name from user_constraints where table_name = 'T';
CONSTRAINT_NAME
------------------------------
BIN$VJSEhlGzcMngQA4KH2h7+A==$0

You will need to explicitly rename these objects to their former names, if you so choose.
Additionally, the following statements are true:

Some constraints, such as FK , can't be flashed back; they are lost.

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Bitmap join indexes are not flashed back.

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Materialized view logs are not placed in the Recycle Bin, so they are lost.

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It's possible that some indexes may have been erased from the Recycle Bin, even
when the table remained (typically under space pressure). So, it's not guaranteed
that all the indexes will be reverted when the table is flashed back before drop.

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