Operation: PARTITION LIST
Option: EMPTY
PARTITION LIST EMPTY does not perform the operation on any partition in the table.
Option: OR
PARTITION LIST OR performs the operation on all table partitions in a disjunction.
Option: SUBQUERY
PARTITION LIST SUBQUERY performs the operation on all list table partitions based on a subquery.
Operation: PARTITION RANGE
Option: EMPTY
PARTITION RANGE EMPTY does not perform the operation on any partition in the table.
Option: OR
PARTITION RANGE OR performs the operation on all range table partitions in a disjunction.
Option: SUBQUERY
PARTITION RANGE SUBQUERY performs the operation on all table partitions based on a subquery.
Execution Plan image:
Row operation.
PROJECTION is used by the INTERSECTION, MINUS, and UNION operations to return a single set of records from the results of multiple queries.
select Company_ID
from COMPANY
MINUS
select Company_ID
from COMPETITOR;
PROJECTION
MINUS
SORT UNIQUE
TABLE ACCESS FULL COMPANY
SORT UNIQUE
TABLE ACCESS FULL COMPETITOR
The Execution Plan shows that after the MINUS operation is performed, the PROJECTION operation resolves the output into a single set of data for output to the user. PROJECTION is always used in conjunction with the MINUS, INTERSECTION, and UNION operations.
The PX BLOCK ITERATOR operation retrieves data from blocks after dividing the scan process between parallel scan slaves.
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