Group rows together based on column values and perform a rollup. No sort is required
This operation was introduced in Oracle 9.0.1
This operation is implemented in the following versions
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Table must be indexed (to allow the NOSORT). Indexed column must be NOT NULL to allow use of the index
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); CREATE INDEX i1 ON t1 (c1);
The table does not need to be analysed
The statement
SELECT /*+ INDEX (t1 i1) */ c1 FROM t1 GROUP BY ROLLUP c1;
generates the following execution plan
0 SELECT STATEMENT Optimizer=CHOOSE 1 0 SORT (GROUP BY NOSORT ROLLUP) 2 1 INDEX (FULL SCAN) OF 'I1'