SQL/MX 3.1 Query Guide (H06.23+, J06.12+)

SQL/MX Operators
HP NonStop SQL/MX Release 3.1 Query Guide—663851-001
7-70
SORT_PARTIAL_GROUPBY_LEAF Operator
operator finalizes the group by at the ESP level. This operator consists of a one-row
aggregate without standard aggregate functions (SUM, MIN, MAX, and so on). The
root portion occurs in the root. The description field for this operator contains:
The following is an example of the SORT_PARTIAL_AGGR_ROOT operator:
prepare TestQuery17 from
select T03.char_100
from PTAB03 T03
where T03.char_100 =
(Select min(T00.char_10)
from PTAB00 T00);
DESCRIPTION
fragment_id ............ 0
parent_frag ............ (none)
fragment_type .......... master
aggregates .............
min(min(DETCAT.DETSCH.PTAB00.CHAR_10))
SORT_PARTIAL_GROUPBY_LEAF Operator
Groupby Group
The SORT_PARTIAL_GROUPBY_LEAF operator executes a partial group by as close
to where the data is read as is cost effective. This strategy reduces the amount of data
that must be redistributed for a query. The operator must always be accompanied by a
SORT_PARTIAL_GROUPBY_ROOT operator above it in the tree, which finalizes the
query.
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
aggregates Expression of the aggregate function. expr(text)
TP663851.fm Page 70 Monday, October 17, 2011 11:48 AM