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qid is a case-sensitive identifier, which represents the query ID. For example:
'QID=MXID01001011194212103659400053369000000085905admin00_2605_S1'
The EXPLAIN function or statement returns the plan that was generated when the query was
prepared. EXPLAIN for QID retrieves all the information from the original plan of the executing
query. The plan is available until the query finishes executing and is removed or deallocated.
Result of the EXPLAIN Function
The result table of the EXPLAIN function describes the access plans for SELECT, INSERT,
DELETE, UPDATE, or CALL statements.
In this description of the result of the EXPLAIN function, an operator tree is a structure that
represents operators used in an access plan as nodes, with at most one parent node for each node
in the tree, and with only one root node.
A node of an operator tree is a point in the tree that represents an event (involving an operator)
in a plan. Each node might have subordinate nodes—that is, each event might generate a
subordinate event or events in the plan.
Column Name
MODULE_NAME
STATEMENT_ NAME
PLAN_ID
SEQ_NUM
OPERATOR
LEFT_CHILD_ SEQ_NUM
RIGHT_CHILD_ SEQ_NUM
TNAME
CARDINALITY
OPERATOR_COST
TOTAL_COST
DETAIL_COST
DESCRIPTION
402
SQL Functions and Expressions
Data Type
Description
CHAR(60)
Reserved for future use.
CHAR(60)
Statement name; truncated on the right if longer than 60
characters.
LARGEINT
Unique system-generated plan ID automatically assigned
by Neoview SQL; generated at compile time.
INT
Sequence number of the current operator in the operator
tree; indicates the sequence in which the operator tree
is generated.
CHAR(30)
Current operator type. For a full list of valid operators,
see the Neoview Query Guide.
INT
Sequence number for the first child operator of the
current operator; null if node has no child operators.
INT
Sequence number for the second child operator of the
current operator; null if node does not have a second
child.
CHAR(60)
For operators in scan group, full name of base table,
truncated on the right if too long for column. If
correlation name differs from table name, simple
correlation name first and then table name in
parentheses.
REAL
Estimated number of rows that will be returned by the
current operator. Cardinality appears as
ROWS/REQUEST in some forms of EXPLAIN output.
For the right child of a nested join, multiply the
cardinality by the number of requests to get the total
number of rows produced by this operator.
REAL
Estimated cost associated with the current operator to
execute the operator.
REAL
Estimated cost associated with the current operator to
execute the operator, including the cost of all subtrees
in the operator tree.
VARCHAR (200)
Cost vector of five items, described in the next table.
VARCHAR (3000)
Additional information about the operator. For a detailed
look at all operators, see the Neoview Query Guide.
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