Appears in a parallel execution plan
This operation was introduced in Oracle 9.2.0. Replaces GRANULE ITERATOR in Oracle 9.0.1 and below
This operation is implemented in the following versions
This operation was replaced in Oracle 10.1 by PX BLOCK (ITERATOR)
This operation appears in the slave process of a parallel query. The execution plan is only generated if the query is executed, therefore it is not sufficient just to explain the query
The execution plan can be observed in V$SQL_PLAN
This example was developed using Oracle 9.2.0
This example requires the following definitions
CREATE TABLE t1 (c1 NUMBER); INSERT INTO t1 VALUES (0);
SELECT /*+ PARALLEL (t1,4) */ c1,COUNT(*) FROM t1 GROUP BY c1;
generates the following execution plan
0 SELECT STATEMENT Optimizer=CHOOSE 1 0 SORT (GROUP BY) 2 1 SORT (GROUP BY) 3 2 TABLE ACCESS (FULL) OF 'T1'
Step 2 executes the following SQL statement using slave processes
SELECT /*+ PIV_GB */ A1.C0 C0,SYS_OP_MSR(COUNT(*)) C1 FROM ( SELECT /*+ NO_EXPAND ROWID(A2) */ A2."C1" C0 FROM "USER1"."T1" PX_GRANULE(0, BLOCK_RANGE, DYNAMIC) A2 ) A1 GROUP BY A1.C0
This generates the following execution plan
0 SELECT STATEMENT Optimizer=CHOOSE 1 0 SORT (GROUP BY) 2 1 GRANULE ITERATOR (ROWID RANGE) 3 2 TABLE ACCESS (BY ROWID RANGE) OF 'T1'