Neoview SQL Reference Manual (R2.5)

Table 2-5 Node Listing Information
DescriptionField
Current operator type, such as FILE_SCAN, HASH_JOIN, NESTED_JOIN,
and so on.
Operator name
Sequence number of the current operator in the query execution plan;
indicates the sequence in which the query plan is generated.
SEQ_NO
Sequence number of the operator’s children (operators that feed data up to
this operator). There can be 0, 1, or 2 children shown as NO CHILDREN,
ONLY CHILD 6, or CHILDREN 5, 7.
Children information
Name of base table, shown only on operators that access the table.TABLE_NAME
Estimated number of requests for execution of this operator. The value is 1
except for the right child operator (inner scan) of a nested-loop join.
REQUESTS_IN
Estimated number of rows returned by the plan or, when REQUESTS_IN is
greater than one, the value is the estimated number of rows returned per
input request.
ROWS_OUT or ROWS/REQUEST
Estimated cost associated with executing the current operator.EST_OPER_COST
Estimated cost associated with execution of the current operator and all
children.
EST_TOTAL_COST
Additional information about the operation. For example, in the case of a
scan, the description field shows scan_type, scan_direction, lock_mode,
access_mode, columns_retrieved, optimization information, and so on. For
details about all operators and their description fields, see the Neoview Query
Guide.
DESCRIPTION
This example uses OPTIONS 'n':
>>explain options 'n' select * from region;
------------------------------------------------------------------ PLAN SUMMARY
MODULE_NAME .............. DYNAMICALLY COMPILED
STATEMENT_NAME ........... NOT NAMED
PLAN_ID .................. 212141478299499838
ROWS_OUT ............... 100
EST_TOTAL_COST ........... 0.01
STATEMENT ................ select * from region;
------------------------------------------------------------------ NODE LISTING
ROOT ====================================== SEQ_NO 3 ONLY CHILD 2
REQUESTS_IN .............. (not found)
ROWS_OUT ............... 100
EST_OPER_COST ............ 0.01
EST_TOTAL_COST ........... 0.01
DESCRIPTION
max_card_est ......... 100
fragment_id ............ 0
parent_frag ............ (none)
fragment_type .......... master
xn_access_mode ......... read_only
xn_autoabort_interval 0
auto_query_retry ....... enabled
plan_version ....... 2,400
SESSION_USERNAME ....... MXID01010130744212141209524355662000000044209superus
er00
LDAP_USERNAME .......... superuser
NVCI_PROCESS ........... ON
SHOWCONTROL_UNEXTERNALI OFF
SCHEMA ................. USR
GENERATE_EXPLAIN ....... ON
select_list ............ NEO.USR.REGION.R_KEY, NEO.USR.REGION.R_NAME,
NEO.USR.REGION.R_COMMENT
EXPLAIN Statement 127