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Oracle Tutorials - Recovered Tables with Indexes

By: FYIcenter.com

(Continued from previous topic...)

What Happens to the Indexes If a Table Is Recovered?

If you dropped a table, and recovered it back from the recycle bin, what happens to its indexes? Are all indexes recovered back automatically? The answer is that all indexes will be recovered, if you recover a dropped table from the recycle bin. However, the indexes' names will not be the original names. Indexes will be recovered with the system assigned names when they were dropped into the cycle bin. The following SQL script shows you this behavior:

ALTER SESSION SET recyclebin = on;
Statement processed.

CREATE TABLE student (id NUMBER(5) PRIMARY KEY,
  first_name VARCHAR(80) NOT NULL,
  last_name VARCHAR(80) NOT NULL,
  birth_date DATE NOT NULL,
  social_number VARCHAR(80) UNIQUE NOT NULL);
Table created.

CREATE INDEX student_birth_date ON student(birth_date);
Index created.

SELECT index_name, table_name, uniqueness 
  FROM USER_INDEXES WHERE table_name = 'STUDENT';
INDEX_NAME              TABLE_NAME            UNIQUENES
----------------------- --------------------- ---------
SYS_C004141             STUDENT               UNIQUE
SYS_C004142             STUDENT               UNIQUE
STUDENT_BIRTH_DATE      STUDENT               NONUNIQUE 

DROP TABLE student;
Table dropped.

SELECT index_name, table_name, uniqueness 
  FROM USER_INDEXES WHERE table_name = 'STUDENT';
no data found

FLASHBACK TABLE student TO BEFORE DROP;
Flashback complete.

SELECT index_name, table_name, uniqueness 
  FROM USER_INDEXES WHERE table_name = 'STUDENT';
INDEX_NAME                     TABLE_NAME UNIQUENES
------------------------------ ---------- ---------
BIN$K47Sg+udQv2tDUW5cWAIrQ==$0 STUDENT    UNIQUE 
BIN$6WI0gc79QNqLSNGp2H2Q1Q==$0 STUDENT    UNIQUE 
BIN$9HwZermkRt+9gonHS/klsQ==$0 STUDENT    NONUNIQUE 

If you have trouble running the FLASHBACK statement on your Web interface, run it with SQL*Plus.

(Continued on next topic...)

1. What Is an Index?
2. How To Run SQL Statements through the Web Interface?
3. How To Create a Table Index?
4. How To List All Indexes in Your Schema?
5. What Is an Index Associated with a Constraint?
6. How To Rename an Index?
7. How To Drop an Index?
8. Can You Drop an Index Associated with a Unique or Primary Key Constraint?
9. What Happens to Indexes If You Drop a Table?
10. How To Recover a Dropped Index?
11. What Happens to the Indexes If a Table Is Recovered?
12. How To Rebuild an Index?
13. How To See the Table Columns Used in an Index?
14. How To Create a Single Index for Multiple Columns?