HASH JOIN (ANTI)

Description

Perform a hash 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 FILTER 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);

Consider the statement

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

In Oracle 9.2 this generates the following execution plan

0     SELECT STATEMENT Optimizer=CHOOSE
1   0   HASH JOIN (ANTI)
2   1     TABLE ACCESS (FULL) OF 'T1'
3   1     VIEW OF 'VW_NSO_1'
4   3       TABLE ACCESS (FULL) OF 'T2'

In Oracle 10.2 this generates the following execution plan

0     SELECT STATEMENT Optimizer=CHOOSE
1   0   HASH JOIN (ANTI)
2   1     TABLE ACCESS (FULL) OF 'T1'
3   1     TABLE ACCESS (FULL) OF 'T2'