WINDOW (NOSORT STOPKEY)

Description

Analytic function

Versions

This operation was introduced in Oracle 10.2

This operation is implemented in the following versions

Example

This example was developed using Oracle 10.2.0.1 on Linux

This example requires the following table definitions

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

    CREATE INDEX i1 ON t1 (c1);

The table must be analysed

    ANALYZE TABLE t1 COMPUTE STATISTICS;

The statement

    SELECT c2,r1 FROM
    (
      SELECT c2, RANK () OVER
      (
        ORDER BY c1
      )
      AS r1
      FROM t1
    ) 
    WHERE r1 < 10;

generates the following execution plan

0     SELECT STATEMENT Optimizer=CHOOSE
1   0   VIEW
2   1   WINDOW (NOSORT STOPKEY)
3   2     TABLE ACCESS (BY INDEX ROWID) OF 'T1'
4   3       INDEX (FULL SCAN) OF 'I1' (NON-UNIQUE)