Frequent Itemset Counting operation
This operation is implemented in the following versions
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This example was developed using Oracle 10.2.0.1 on Linux
This example requires the following object definitions
CREATE TABLE t1 ( t1 NUMBER, t2 NUMBER ); CREATE TYPE ty1 AS TABLE OF NUMBER; /
The statement
SELECT CAST (itemset AS ty1) itemset, support, length, total_tranx FROM TABLE ( dbms_frequent_itemset.fi_transactional ( CURSOR (SELECT c1,c2 FROM t1), -- tranx_cursor 0.6, -- support_threshold 2, -- itemset_length_min 5, -- itemset_length_max NULL, -- including_items NULL -- excluding_items ) );
generates the following execution plan
0 SELECT STATEMENT Optimizer=CHOOSE 1 0 FIC RECURSIVE ITERATION 2 1 FIC LOAD ITEMSETS 3 2 FREQUENT ITEMSET COUNTING 4 3 SORT (GROUP BY NOSORT) 5 4 BITMAP CONVERSION (COUNT) 6 5 FIC LOAD BITMAPS 7 6 SORT (CREATE INDEX) 8 7 BITMAP CONSTRUCTION 9 8 FIC ENUMERATE FEED 10 9 SORT (ORDER BY) 11 10 TABLE ACCESS (FULL) OF 'T1' 12 3 TABLE ACCESS (FULL) OF 'SYS_TEMP_0FD9D661A_69C79C'