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
7-87
UNPACK Operator
The following is an example of the UNIQUE_UPDATE operator:
prepare TestQuery27 from
UPDATE tt22
SET f2 = 1
WHERE f1 = 2009;
DESCRIPTION
olt_optimization ....... used
fragment_id ............ 2
parent_frag ............ 0
fragment_type .......... dp2
Scan_Direction ......... forward
olt_optimization ....... used
olt_opt_lean ........... not used
iud_type ............... unique_update DETCAT.DETSCH.TT22
lock_mode .............. not specified, defaulted to lock
cursor
access_mode ............ not specified, defaulted to read
committed
columns_retrieved ...... 2
new_rec_expr ........... (F2 assign 1)
key ...................... (F1 = 2009)
UNPACK Operator
Rowset Group
Use the UNPACK operator in a query plan when an array is used as input in a query
(for example, inserting rows from rowset arrays). The UNPACK operator extracts the
new_rec_expr Computation of the row to be updated expr(text)
predicate Expression specified on WHERE clause that is
not reflected in the begin and end predicates.
expr(text)
key Expression of the key predicate. expr(text)
index_key Expression of the key predicates on index. expr(text)
olt_optimization Indicates whether an optimization for short,
simple operations is used. The value used or
not used.
text
olt_opt_lean Indicates for short, simple operations whether a
further optimization that reduces the physical
size of the plan is used. Its value is used or not
used.
text
part_key_predicate Predicate specified on the partitioning key.
Displayed only if partitioning key differs from
clustering key.
expr(text)
check_constraint Check constraints in the update table. expr(text)
iud_type Type of update followed by table or index name. expr(text)
TP663851.fm Page 87 Wednesday, January 30, 2013 5:37 PM