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
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SUBSET_DELETE Operator
The following is an example of the SPLIT_TOP operator:
PREPARE TestQuery19 FROM
select cust_id, count(*) as order_count from orders
where order_date > (date '2001-01-12') group by cust_id order by
cust_id;
DESCRIPTION
fragment_id ............ 0
parent_frag ............ (none)
fragment_type .......... master
olt_optimization ....... not used
parent_processes ....... 1
child_processes .......... 3 parent_partitioning_fun grouped
1 to 3,PAPA with 3 PA(s),
exactly 1 partition
child_partitioning_func range
partitioned 3 ways on
(T03.SINT32_UNIQ)
SUBSET_DELETE Operator
DAM Subset Group
The SUBSET_DELETE operator describes a portion of an execution plan that details
how a certain access path is scanned: it deletes more than one row. A subset
operation performs the read and delete in a combined operation. This operation differs
from CURSOR_DELETE, which performs the read and delete in separate operations.
The CURSOR_DELETE operation also involves more messages.
This 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
iud_type Type of delete followed by table or index name. expr(text)
predicate Expression specified in WHERE clause. expr(text)
part_key_predicate Predicate expression specified on partitioning
key. It is displayed only if partitioning key differs
from clustering key.
expr(text)
begin_key Expression of the begin key predicate. expr(text)
TP663851.fm Page 77 Wednesday, January 30, 2013 5:37 PM