SQL/MX 3.1 Query Guide (H06.23+, J06.12+)

SQL/MX Operators
HP NonStop SQL/MX Release 3.1 Query Guide—663851-001
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EXPLAIN Operator
EXPLAIN Operator
Stored Function Group
The EXPLAIN operator executes a stored function. The operator for an EXPLAIN
operator is always EXPLAIN.
EXPLAIN has no child nodes. The description field for this operator contains:
The following is an example for EXPLAIN operator:
prepare TestQuery28 from
SELECT * FROM TABLE (EXPLAIN (NULL,'%'));
DESCRIPTION
fragment_id ............ 0
parent_frag ............ (none)
fragment_type .......... master
function_parameters ...... NULL, '%'
EXPR Operator
Tuple Group
The EXPR operator calculates an expression for each row it receives from its child
node and returns that expression to its parent node.
The EXPR operator has one child node. The description field for this operator contains:
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 of the current
fragment. The value is (none) for the
master executor.
integer
fragment_type Master, ESP, or DP2. text
function_parameters Parameters from the call to the EXPLAIN
function.
expr(text)
Token Followed by ... Data Type
tuple_expr The tuple produced by this node expr(text)
TP663851.fm Page 16 Monday, October 17, 2011 11:48 AM