SQL/MX 3.2.1 Query Guide (H06.26+, J06.15+)

SQL/MX Operators
HP NonStop SQL/MX Release 3.2.1 Query Guide—663851-003
7-85
UNIQUE_DELETE Operator
SELECT count(*) FROM table_a
WHERE (table_b.col1,table_b.col2)=
(table_a.col1,table_a.col2)
AND table_a.col3 = 1
)
WHERE (table_b.col1,table_b.col2)=
(newrow.col1,newrow.col2);
insert into table_b values('A', 1, 1, 0);
Prepare TestQuery11 from
insert into table_a values('A', 1, 1);
DESCRIPTION
fragment_id ............ 0
parent_frag ............ (none)
fragment_type .......... master
union_type ............... merge
UNIQUE_DELETE Operator
DAM Unique Group
The UNIQUE_DELETE operator describes a portion of an execution plan that works on
one row only. It deletes zero or one row.
The UNIQUE_DELETE operator has no child nodes. The description field for this
operator contains the following:
Token Followed by ... Data Type
fragment_id A sequential number assigned to the fragment.
0 is always the master executor and 1 is
reserved for the EXPLAIN plan. Numbers 2 to n
will be ESP or DAM fragments.
integer
parent_frag The fragment_id for the parent of the current
fragment. The value is (none) for the master
executor.
integer
fragment_type Master, ESP, or DP2. text
index_key Expression of the begin key predicates on
index.
expr(text)
key Expression of the key predicate. expr(text)
part_key_predicate Predicate expression specified on partitioning
key. It is displayed only if partitioning key differs
from clustering key.
expr(text)
check_constraint Check constraints in the delete table. expr(text)
olt_optimization Indicates whether an optimization for short,
simple operations is used. Its value is used or
not used.
text
TP663851.fm Page 85 Wednesday, January 30, 2013 5:37 PM