INDEX (FULL SCAN)

Description

Perform an index full scan

Versions

This operation is implemented in the following versions

7.3.4
8.0.4
8.0.5
8.0.6
8.1.5
8.1.6
8.1.7
9.0.1
9.2.0
10.1.0
10.2.0

Example

Example 1

In this example the indexed columns must have a NOT NULL constraint

This example was developed using Oracle 9.2.0.1 on Windows 2000

This example requires the following table definition

    CREATE TABLE t1 (c1 NUMBER NOT NULL,c2 NUMBER);

    CREATE INDEX i1 ON t1 (c1);

The table does not need to be analysed

The statement

    SELECT /*+ INDEX (t1 i1) */ c1
    FROM t1;

generates the following execution plan

0     SELECT STATEMENT Optimizer=CHOOSE
1   0   INDEX (FULL SCAN) OF 'I1' (NON-UNIQUE)
Example 2

This example demonstrates that if an IS NOT NULL predicate is used in the WHERE clause, a NOT NULL constraint is not required

This example was developed using Oracle 9.2.0.1 on Windows 2000

This example requires the following table definition

    CREATE TABLE t1 (c1 NUMBER,c2 NUMBER);

    CREATE INDEX i1 ON t1 (c1);

The table does not need to be analysed

The statement

    SELECT /*+ INDEX (t1 i1) */ c1
    FROM t1
    WHERE c1 IS NOT NULL;

generates the following execution plan

0     SELECT STATEMENT Optimizer=CHOOSE
1   0   INDEX (FULL SCAN) OF 'I1' (NON-UNIQUE)