Perform a hash anti join between two row sources
This operation is implemented in the following versions
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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'