Table Access (Sample By Rowid Range)

TABLE ACCESS (SAMPLE BY ROWID RANGE)

Description

Performs a scan of a sample of the blocks in the table up to the high water mark using the supplied ROWID range

Versions

This operation was introduced in Oracle 8.1.6

This operation is implemented in the following versions

8.1.6

8.1.7

9.0.1

9.2.0

10.1.0

10.2.0

Example

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);

The table does not need to be analysed

The statement

    SELECT c1 FROM t1 SAMPLE (10)
    WHERE ROWID > 
    (
        SELECT MIN (ROWID) FROM t1
    );

generates the following execution plan

0     SELECT STATEMENT Optimizer=CHOOSE
1   0   TABLE ACCESS (SAMPLE BY ROWID RANGE) OF 'T1'
2   1     SORT (AGGREGATE)
3   2       TABLE ACCESS (FULL) OF 'T1')