PX BLOCK ITERATOR

Description

Parallel slave process - iterates through a set of blocks

Versions

This operation is implemented in the following versions

Replaces GRANULE ITERATOR family of operations in Oracle 9.2

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
    )
    PARALLEL 2;

The statement

    SELECT COUNT(*) FROM t1;

generates the following execution plan

0     SELECT STATEMENT Optimizer=CHOOSE
1   0   SORT (AGGREGATE)
2   1     PX COORDINATOR
3   2       PX SEND (QC (RANDOM))
4   3         SORT (AGGREGATE)
5   4           PX BLOCK ITERATOR
6   5             TABLE ACCESS (FULL) OF 'T1'