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

Data TypeToken DescriptionToken
expr(text)Expression of the join predicatejoin_predicate
expr(text)Expression of the WHERE clause that is not included in a
hash_join_predicate or one of the child scans
selection_predicates
The difference between join_predicate and hash_join_predicate tokens is that the former are the
non-equijoin predicates. The latter are equijoin predicates that you use to help build and probe
the hash table.
ORDERED_HASH_ANTI_SEMI_JOIN
The ORDERED_HASH_ANTI_SEMI_JOIN operator returns only one row for every outer row
when no match occurs. This operator preserves the order of the outer table and does not overflow
to disk. The reuse feature allows reuse of the hash table for subsequent requests within the same
query. This operator is chosen only if the inner table is small enough to fit in memory.
The ORDERED_HASH_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 or anti-semi joinjoin_type
textName of join method: hashjoin_method
text1 for Type1 or 2 for Type2, depending on parallel join algorithmparallel_join_type
expr(text)Expression of the join predicatehash_join_predicate
expr(text)List of values that cause the hash table to be rebuilt when values
change
reuse_comparison_values
expr(text)Expression of the join predicatejoin_predicate
expr(text)Expression of the WHERE clause that is not included in a
hash_join_predicate or one of the child scans
selection_predicates
LEFT_ORDERED_HASH_JOIN Operator
The LEFT_ORDERED_HASH_JOIN operator returns an unmatched outer row even when it does
not find a match in the inner table. Null values are supplied for the missing inner rows. The
LEFT_ORDERED_HASH_JOIN operator differs from the LEFT_HYBRID_HASH_JOIN in that
it preserves the order of the outer table and does not overflow to disk. In addition, the reuse
feature enables reuse of the hash table for subsequent requests within the same query. This
operator is chosen only if the inner table is small enough to fit in memory.
Operators and Description Fields 33