Neoview Query Guide (R2.3, R2.4, R2.5)

Data TypeToken DescriptionToken
textName of join method: mergejoin_method
text1 for Type1 or 2 for Type2, depending on parallel join algorithmparallel_join_type
expr(text)Expression of the join predicatemerge_join_predicate
expr(text)Expression of the WHERE clause that is not included in the
merge_join_predicate or in a selection_predicates of any children
selection_predicates
MERGE_SEMI_JOIN Operator
The MERGE_SEMI_JOIN operator returns one row for the first match it finds in the inner table.
Conversely, MERGE_JOIN returns a row for all matches in the inner table. See “MERGE_JOIN
Operator” (page 27).
The MERGE_SEMI_JOIN operator has two child operators. The description field for this operator
contains:
Data TypeToken DescriptionToken
integerA sequential number assigned to the fragment. 0 is always master
executor and 1 is reserved for the Explain plan. Numbers 2 to n will be
ESP or DAM fragments.
fragment_id
integerThe fragment_id for the parent fragment of the current fragment. Value
is (none) for master executor.
parent_frag
textmaster, ESP, or DAMfragment_type
textInner-semi or natural semi-joinjoin_type
textName of join method: mergejoin_method
text1 for Type1 or 2 for Type2, depending on parallel join algorithmparallel_join_type
expr(text)Expression of the join predicatemerge_join_predicate
expr(text)Expression of the WHERE clause that is not included in the
merge_join_predicate or in a selection_predicates of any children
selection_predicates
MERGE_ANTI_SEMI_JOIN Operator
The MERGE_ANTI_SEMI_JOIN operator returns rows only when no match occurs in the inner
table. The operator discards all rows that have a match. Also see “MERGE_JOIN Operator”
(page 27) and “MERGE_SEMI_JOIN Operator” (page 28).
The MERGE_ANTI_SEMI_JOIN operator has two child operators. The description field for this
operator contains:
Data TypeToken DescriptionToken
integerA sequential number assigned to the fragment. 0 is always master executor
and 1 is reserved for the Explain plan. Numbers 2 to n will be ESP or DAM
fragments.
fragment_id
integerThe fragment_id for the parent fragment of the current fragment. Value
is (none) for master executor.
parent_frag
textmaster, ESP, or DAMfragment_type
textInner anti-semi or natural anti-semi-joinjoin_type
textName of join method: mergejoin_method
text1 for Type1 or 2 for Type2, depending on parallel join algorithmparallel_join_type
28 Query Plan Operators