Neoview Query Guide (R2.3, R2.4, R2.5)

ManualsBrandsHP ManualsSoftwareHP Neoview Release 2.5 Software

TUPLE_FLOW Operator

The TUPLE_FLOW operator describes a portion of an execution plan that typically involves an

insert-select or a rowset insert, implemented as a type 1, matching partitions nested join. All

rows from the outer table are selected and inserted into the inner table. This operator enables

data to flow from one child to the other. The join_predicate and selection_predicates expressions

are empty. As with the nested join, for the inner child tree you need to review the PROBES field

of the COST_DETAILS panel in NPA to find the estimated cardinality for the operation.

This operator facilitates fast and efficient parallel, sequential inserts and is frequently preceded

by a sort operation.

The TUPLE_FLOW operator has two child operators. The description field for this operator

contains:

Data TypeToken DescriptionToken

integerA sequential number assigned to the fragment. 0 is always master

executor and 1 is reserved for the Explain plan. Numbers 2 to n will be

ESP or DAM fragments.

fragment_id

integerThe fragment_id for the parent fragment of the current fragment. Value

is (none) for master executor.

parent_frag

textmaster, ESP, or DAMfragment_type

textInner joinjoin_type

textName of join method: nested or in-order nested joinjoin_method

text1 for Type1 or 2 for Type2, depending on parallel join algorithmparallel_join_type

expr(text)Expression of the ON clause that has not been pushed down to the inner

scan, typically empty

join_predicate

expr(text)Expression of the WHERE clause that has not been pushed down to the

inner scan, typically empty

selection_predicates

Merge Joins

In a merge join, both tables are required to be sorted on the join column. A buffer of rows is read

from the inner and outer tables, and a row from the outer table is used to match inner table rows

in a match-merge pattern.

MERGE_JOIN Operator

The MERGE_JOIN operator describes a portion of an execution plan that involves a merge join.

This operator joins the data from its two child operators. The data streams from both children

must be in the same order. The operator joins all matching rows from each data stream. The

MERGE_JOIN operator works only with equijoins.

The MERGE_JOIN operator has two child operators. The description field for this operator