MERGE JOIN (ANTI)

Description

Performs a merge anti join between two row sources

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

Note that the columns involved in the anti-join must both have NOT NULL constraints. Other permutations result in FILER execution plans.

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 TABLE t2 (c1 NUMBER NOT NULL,c2 NUMBER);

The table does not need to be analysed

The statement

    SELECT c2
    FROM t1
    WHERE c1 NOT IN
    (
      SELECT /*+ MERGE_AJ */ c1 FROM t2
    );

generates the following execution plan

0     SELECT STATEMENT Optimizer=CHOOSE
1   0   MERGE JOIN (ANTI)
2   1     SORT (JOIN)
3   2       TABLE ACCESS (FULL) OF 'T1'
4   1     SORT (UNIQUE)
5   4       VIEW OF 'VW_NSO_1'
6   5         TABLE ACCESS (FULL) OF 'T2'