HASH JOIN (BUFFERED)

Description

Hash Join using buffered row source

Versions

This operation is implemented in the following versions

10.1.0
10.2.0

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,
      c2 NUMBER
    );

    CREATE TABLE t2
    (
      c1 NUMBER,
      c2 NUMBER
    );

The statement

    SELECT /*+ PARALLEL (t2,4) */ t2.c2
    FROM t1,t2
    WHERE t1.c1 = t2.c1;

generates the following execution plan

0     SELECT STATEMENT Optimizer=CHOOSE
1   0   PX COORDINATOR
2   1     PX SEND (QC (RANDOM))
3   2       HASH JOIN (BUFFERED)
4   3         BUFFER (SORT)
5   4           PX RECEIVE
6   5             PX SEND (HASH)
7   6               TABLE ACCESS (FULL) OF 'T1'
8   3         PX RECEIVE
9   8           PX SEND (HASH)
10  9             PX BLOCK ITERATOR
11 10               TABLE ACCESS (FULL) OF 'T2'