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

SQL/MX Operators
HP NonStop SQL/MX Query Guide—540437-005
7-80
UNPACK Operator
The example of the UNIQUE_UPDATE operator is based on:
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
elements from the array to use in the query. For more information about rowsets and
arrays, see the SQL/MX Programming Manual for C and COBOL.
The UNPACK operator has one child. The description field for this operator contains:
part_key_predicate Predicate specified on the partitioning key.
Displayed only if partitioning key differs from
clustering key.
expr(text)
check_constraint Check constrains in the update table. expr(text)
iud_type Type of update followed by table or index name. expr(text)
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 fragment of the
current fragment. The value is (none) for the
master executor.
integer
fragment_type Master, ESP, or DP2 text