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

Reviewing Query Execution Plans
HP NonStop SQL/MX Query Guide—540437-005
4-7
Using the EXPLAIN Statement to Review the
Execution Plan
LEFT_CHILD_SEQ_NUM
RIGHT_CHILD_SEQ_NUM
TNAME
CARDINALITY OPERATOR_COST TOTAL_COST DETAIL_COST
DESCRIPTION
?
EXPL_NAME__
211977924124011276 1 FILE_SCAN ? ?
SAMDBCAT.PERSNL.EMPLOYEE
2.0000000E+000 2.0646531E-002 2.0646531E-002
CPU_TIME: 0.000287
IO_TIME: 0.020647
MSG_TIME: 0
IDLETIME: 0
PROBES: 1
scan_type: file_scan SAMDBCAT.PERSNL.EMPLOYEE
scan_direction: forward
key_type: simple
lock_mode: not specified
access_mode: not specified
columns_retrieved: 6
fast_scan: used
fast_replydata_move: used
key_columns: indexcol(SAMDBCAT.PERSNL.EMPLOYEE.EMPNUM)
executor_predicates: (indexcol(SAMDBCAT.PERSNL.EMPLOYEE.SALARY)
40000.00) and (indexcol(SAMDBCAT.PERSNL.EMPLOYEE.JOBCODE) = 450)
begin_key: (indexcol(SAMDBCAT.PERSNL.EMPLOYEE.EMPNUM) = 0)
end_key: (indexcol(SAMDBCAT.PERSNL.EMPLOYEE.EMPNUM) = 9999)
?
EXPL_NAME__
211977924124011276 2 PARTITION_ACCESS 1
?
2.0000000E+000 2.0422223E-003 2.0646531E-002
CPU_TIME: 0.002329
IO_TIME: 0.020647
MSG_TIME: 0
IDLETIME: 0
PROBES: 1
buffer_size: 31000
record_length: 44
?
EXPL_NAME__
211977924124011276 3 ROOT 2
?
2.0000000E+000 9.8000802E-002 1.1864653E-001
CPU_TIME: 0.002433
IO_TIME: 0.020647
MSG_TIME: 0
IDLETIME: 0.098
PROBES: 1
statement_index: 0
statement: SELECT last_name, first_name, salary from