Here I'm going to describe how to get execution plan result for specific query. For example we have a table with test data:
CREATE TABLE indexed_data (
id NUMBER(19,0) NOT NULL CONSTRAINT indexed_data_pk PRIMARY KEY,
data NUMBER(19,0) NOT NULL
);
CREATE INDEX indexed_data_data_inx ON indexed_data (
data
) NOLOGGING;
insert into indexed_data(id, data) values (1, 1);
insert into indexed_data(id, data) values (2, 2);
insert into indexed_data(id, data) values (3, 3);
And want to know is indexed_data_data_inx index used in query:
SELECT * from indexed_data WHERE data = 0;
This two queries will helps you:
EXPLAIN PLAN
SET statement_id = 'indexed_data_ex_plan' FOR
SELECT * from indexed_data WHERE data = 0;
SELECT PLAN_TABLE_OUTPUT FROM TABLE(DBMS_XPLAN.DISPLAY(NULL, 'indexed_data_ex_plan','BASIC'));
As result you will get:
Plan hash value: 1246571312
-------------------------------------------------------------
| Id | Operation | Name |
-------------------------------------------------------------
| 0 | SELECT STATEMENT | |
| 1 | TABLE ACCESS BY INDEX ROWID | INDEXED_DATA |
| 2 | INDEX RANGE SCAN | INDEXED_DATA_DATA_INX |
-------------------------------------------------------------
CREATE TABLE indexed_data (
id NUMBER(19,0) NOT NULL CONSTRAINT indexed_data_pk PRIMARY KEY,
data NUMBER(19,0) NOT NULL
);
CREATE INDEX indexed_data_data_inx ON indexed_data (
data
) NOLOGGING;
insert into indexed_data(id, data) values (1, 1);
insert into indexed_data(id, data) values (2, 2);
insert into indexed_data(id, data) values (3, 3);
And want to know is indexed_data_data_inx index used in query:
SELECT * from indexed_data WHERE data = 0;
This two queries will helps you:
EXPLAIN PLAN
SET statement_id = 'indexed_data_ex_plan' FOR
SELECT * from indexed_data WHERE data = 0;
SELECT PLAN_TABLE_OUTPUT FROM TABLE(DBMS_XPLAN.DISPLAY(NULL, 'indexed_data_ex_plan','BASIC'));
As result you will get:
Plan hash value: 1246571312
-------------------------------------------------------------
| Id | Operation | Name |
-------------------------------------------------------------
| 0 | SELECT STATEMENT | |
| 1 | TABLE ACCESS BY INDEX ROWID | INDEXED_DATA |
| 2 | INDEX RANGE SCAN | INDEXED_DATA_DATA_INX |
-------------------------------------------------------------