SQL/MX 2.x Query Guide (H06.04+, J06.03+)

SQL/MX Operators
HP NonStop SQL/MX Query Guide—540437-005
7-40
MERGE_JOIN Operator
The example of MERGE_ANTI_SEMI_JOIN is based on:
Control Query Default nested_joins 'off';
Control Query Default hash_joins 'off';
PREPARE TestQuery3a FROM
SELECT s_nationkey, s_suppkey
FROM supplier
WHERE s_suppkey NOT IN
( SELECT ps_suppkey from partsupp)
GROUP BY s_nationkey, s_suppkey
ORDER BY s_nationkey, s_suppkey;
DESCRIPTION
fragment_id ............ 0
parent_frag ............ (none)
fragment_type .......... master
join_type .............. inner anti-semi
join_method ............ merge
merge_join_predicate ... (DETCAT.DETSCH.SUPPLIER.S_SUPPKEY =
DETCAT.DETSCH.PSX1.PS_SUPPKEY)
MERGE_JOIN Operator
Join Group
The MERGE_JOIN operator describes a portion of an execution plan that involves a
merge join. This operator joins the data from its two child nodes. The data streams
from both children must be in the same order. The operator joins all matching rows
from each data stream. The MERGE_JOIN operator works only with equijoins.
fragment_type Master, ESP, or DP2. text
merge_join_predicate Expression of the join predicate. expr(text)
join_type Inner, left, natural, inner semi, or inner anti-semi-
join.
text
join_method Name of join method: merge text
parallel_join_type Type1 or Type2, depending on parallel join
algorithm.
text
selection_predicate Expression of the HAVING clause. expr(text)