You can get information on your indexes from user_indexes.
SQL> desc user_indexes;
Name Null? Type
---------------------------
INDEX_NAME NOT NULL VARCHAR2(30)
INDEX_TYPE VARCHAR2(27)
TABLE_OWNER NOT NULL VARCHAR2(30)
TABLE_NAME NOT NULL VARCHAR2(30)
TABLE_TYPE VARCHAR2(11)
UNIQUENESS VARCHAR2(9)
COMPRESSION VARCHAR2(8)
PREFIX_LENGTH NUMBER
TABLESPACE_NAME VARCHAR2(30)
INI_TRANS NUMBER
MAX_TRANS NUMBER
INITIAL_EXTENT NUMBER
NEXT_EXTENT NUMBER
MIN_EXTENTS NUMBER
MAX_EXTENTS NUMBER
PCT_INCREASE NUMBER
PCT_THRESHOLD NUMBER
INCLUDE_COLUMN NUMBER
FREELISTS NUMBER
FREELIST_GROUPS NUMBER
PCT_FREE NUMBER
LOGGING VARCHAR2(3)
BLEVEL NUMBER
LEAF_BLOCKS NUMBER
DISTINCT_KEYS NUMBER
AVG_LEAF_BLOCKS_PER_KEY NUMBER
AVG_DATA_BLOCKS_PER_KEY NUMBER
CLUSTERING_FACTOR NUMBER
STATUS VARCHAR2(8)
NUM_ROWS NUMBER
SAMPLE_SIZE NUMBER
LAST_ANALYZED DATE
DEGREE VARCHAR2(40)
INSTANCES VARCHAR2(40)
PARTITIONED VARCHAR2(3)
TEMPORARY VARCHAR2(1)
GENERATED VARCHAR2(1)
SECONDARY VARCHAR2(1)
BUFFER_POOL VARCHAR2(7)
USER_STATS VARCHAR2(3)
DURATION VARCHAR2(15)
PCT_DIRECT_ACCESS NUMBER
ITYP_OWNER VARCHAR2(30)
ITYP_NAME VARCHAR2(30)
PARAMETERS VARCHAR2(1000)
GLOBAL_STATS VARCHAR2(3)
DOMIDX_STATUS VARCHAR2(12)
DOMIDX_OPSTATUS VARCHAR2(6)
FUNCIDX_STATUS VARCHAR2(8)
JOIN_INDEX VARCHAR2(3)
IOT_REDUNDANT_PKEY_ELIM VARCHAR2(3)
DROPPED VARCHAR2(3)
status Indicates whether the index is valid. Set to VALID or INVALID.
SQL>
SQL> -- create demo table
SQL> create table Employee(
2 ID VARCHAR2(4 BYTE) NOT NULL,
3 First_Name VARCHAR2(10 BYTE),
4 Last_Name VARCHAR2(10 BYTE),
5 Start_Date DATE,
6 End_Date DATE,
7 Salary Number(8,2),
8 City VARCHAR2(10 BYTE),
9 Description VARCHAR2(15 BYTE)
10 )
11 /
Table created.
SQL>
SQL> -- prepare data
SQL> insert into Employee(ID, First_Name, Last_Name, Start_Date, End_Date, Salary, City, Description)
2 values ('01','Jason', 'Martin', to_date('19960725','YYYYMMDD'), to_date('20060725','YYYYMMDD'), 1234.56, 'Toronto', 'Programmer')
3 /
1 row created.
SQL> insert into Employee(ID, First_Name, Last_Name, Start_Date, End_Date, Salary, City, Description)
2 values('02','Alison', 'Mathews', to_date('19760321','YYYYMMDD'), to_date('19860221','YYYYMMDD'), 6661.78, 'Vancouver','Tester')
3 /
1 row created.
SQL> insert into Employee(ID, First_Name, Last_Name, Start_Date, End_Date, Salary, City, Description)
2 values('03','James', 'Smith', to_date('19781212','YYYYMMDD'), to_date('19900315','YYYYMMDD'), 6544.78, 'Vancouver','Tester')
3 /
1 row created.
SQL> insert into Employee(ID, First_Name, Last_Name, Start_Date, End_Date, Salary, City, Description)
2 values('04','Celia', 'PRice', to_date('19821024','YYYYMMDD'), to_date('19990421','YYYYMMDD'), 2344.78, 'Vancouver','Manager')
3 /
1 row created.
SQL> insert into Employee(ID, First_Name, Last_Name, Start_Date, End_Date, Salary, City, Description)
2 values('05','Robert', 'Black', to_date('19840115','YYYYMMDD'), to_date('19980808','YYYYMMDD'), 2334.78, 'Vancouver','Tester')
3 /
1 row created.
SQL> insert into Employee(ID, First_Name, Last_Name, Start_Date, End_Date, Salary, City, Description)
2 values('06','Linda', 'Green', to_date('19870730','YYYYMMDD'), to_date('19960104','YYYYMMDD'), 4322.78,'New York', 'Tester')
3 /
1 row created.
SQL> insert into Employee(ID, First_Name, Last_Name, Start_Date, End_Date, Salary, City, Description)
2 values('07','David', 'Larry', to_date('19901231','YYYYMMDD'), to_date('19980212','YYYYMMDD'), 7897.78,'New York', 'Manager')
3 /
1 row created.
SQL> insert into Employee(ID, First_Name, Last_Name, Start_Date, End_Date, Salary, City, Description)
2 values('08','James', 'Cat', to_date('19960917','YYYYMMDD'), to_date('20020415','YYYYMMDD'), 1232.78,'Vancouver', 'Tester')
3 /
1 row created.
SQL>
SQL>
SQL>
SQL> -- display data in the table
SQL> select * from Employee
2 /
ID FIRST_NAME LAST_NAME START_DAT END_DATE SALARY CITY DESCRIPTION
---- ---------- ---------- --------- --------- ---------- ---------- ---------------
01 Jason Martin 25-JUL-96 25-JUL-06 1234.56 Toronto Programmer
02 Alison Mathews 21-MAR-76 21-FEB-86 6661.78 Vancouver Tester
03 James Smith 12-DEC-78 15-MAR-90 6544.78 Vancouver Tester
04 Celia PRice 24-OCT-82 21-APR-99 2344.78 Vancouver Manager
05 Robert Black 15-JAN-84 08-AUG-98 2334.78 Vancouver Tester
06 Linda Green 30-JUL-87 04-JAN-96 4322.78 New York Tester
07 David Larry 31-DEC-90 12-FEB-98 7897.78 New York Manager
08 James Cat 17-SEP-96 15-APR-02 1232.78 Vancouver Tester
8 rows selected.
SQL>
SQL>
SQL> CREATE INDEX employee_last_name_func_idx
2 ON employee(UPPER(last_name));
Index created.
SQL> SELECT first_name, last_name
2 FROM employee
3 WHERE last_name = UPPER('PRICE');
no rows selected
SQL>
SQL> SELECT index_name, table_name, uniqueness, status
2 FROM user_indexes
3 WHERE table_name IN ('EMPLOYEE');
INDEX_NAME TABLE_NAME UNIQUENES STATUS
------------------------------ ------------------------------ --------- --------
EMPLOYEE_LAST_NAME_FUNC_IDX EMPLOYEE NONUNIQUE VALID
SQL>
SQL> drop index employee_last_name_func_idx;
SQL> -- clean the table
SQL> drop table Employee
2 /
Table dropped.
SQL>
SQL>
SQL>