SQL/MX 2.x Query Guide (G06.24+, H06.03+)

Operators and Operator Groups
HP NonStop SQL/MX Query Guide—523728-003
7-50
SUBSET_DELETE Operator
AND n1.n_regionkey = r1.r_regionkey
AND r1.r_name = 'EUROPE’
ORDER BY s_acctbal desc, n_name, s_name, p_partkey;
? XX
211862597476194167 24 SPLIT_TOP
2 3 ?
1.0000000E+002 6.5439477E-002 2.5947284E-001
CPU_TIME: 0.066973 IO_TIME: 0.020272 MSG_TIME: 0.012804
IDLETIME: 0.1925 PROBES: 1
top_degree_parallelism: 1
bottom_degree_parallelism: 12
top_num_data_streams: 1
bottom_num_data_streams: 12
bottom_partitioning_function: logphys partitioned(grouping, PAPA
with 12 PA(s), log=exactly 1 partition, phys=range partitioned
12 ways on (([1377]equiv(SUPPLIER.S_NATIONKEY) )))
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 example of the SUBSET_DELETE operator is based on:
DELETE FROM $big18a.wisc32m.bbase WHERE unique2 < 32000;
. . 1 subset_delete
part_key_predicates: (equiv(BBASE.UNIQUE2) < 32000)
Token Followed by ... Data Type
begin_key Expression of the begin key
predicates
expr(text)
end_key Expression of the end key
predicates
expr(text)
scan_type Information on indexes text
scan_direction Forward or reverse text
lock_mode No lock, share lock, or
exclusive lock
text
access_mode Read committed, read
uncommitted, serializable
text
columns_retrieved Estimate of the number of
columns to be returned
integer