Oracle Coherence for C++ API: QueryRecorder Class Reference

Detailed Description

This parallel aggregator used to produce a QueryRecord object that contains an estimated or actual cost of the query execution for a given filter.

For example, the following code will return a QueryPlan, containing the estimated query cost and corresponding execution steps.

QueryRecorder::Handle hAgent = QueryRecorder::create(QueryRecorder::explain); QueryRecord::View vRecord = cast<QueryRecord::View>(hCache->aggregate(filter, agent));

Since:

Coherence 3.7.1

Author:

tb 2011.05.26

Public Types

enum

RecordType { explain, trace }

RecordType enum specifies whether the QueryRecorder should be used to produce a QueryRecord object that contains an estimated or an actual cost of the query execution. More...

typedef spec::Handle

Handle

QueryRecorder Handle definition.

typedef spec::View

View

QueryRecorder View definition.

typedef spec::Holder

Holder

QueryRecorder Holder definition.

Public Member Functions

QueryRecorder (QueryRecorder::RecordType type)

Construct a QueryRecorder.

virtual
QueryRecorder::RecordType

getType () const

Get the record type for this query recorder.

virtual Object::Holder

aggregate (Set::View vSetEntries)

Process a set of InvocableMap::Entry objects in order to produce an aggregated result.

Parameters:

vSetEntries

a Set of read-only InvocableMap::Entry objects to aggregate

Returns:: the aggregated result from processing the entries

virtual
InvocableMap::EntryAggregator::Handle

getParallelAggregator ()

Get an aggregator that can take the place of this aggregator in situations in which the InvocableMap can aggregate in parallel.

Returns:: the aggregator that will be run in parallel

virtual Object::Holder

aggregateResults (Collection::View vCollResults)

Aggregate the results of the parallel aggregations.

Parameters:

vCollResults

the parallel aggregation results

Returns:: the aggregation of the parallel aggregation results

virtual void

readExternal (PofReader::Handle hIn)

virtual void

writeExternal (PofWriter::Handle hOut) const

Protected Member Functions

QueryRecorder ()

Default constructor (necessary for the PortableObject interface).

Protected Attributes

enum RecordType

m_type

This aggregator record type.

Member Enumeration Documentation

enum RecordType

RecordType enum specifies whether the QueryRecorder should be used to produce a QueryRecord object that contains an estimated or an actual cost of the query execution.

Enumerator:

explain	Produce a QueryRecord object that contains an estimated cost of the query execution.
trace	Produce a QueryRecord object that contains the actual cost of the query execution.

Constructor & Destructor Documentation

QueryRecorder ( QueryRecorder::RecordType type )

Construct a QueryRecorder.

Parameters:

type

the type for this aggregator

Member Function Documentation

virtual QueryRecorder::RecordType getType ( ) const [virtual]

Get the record type for this query recorder.

Returns:: the record type enum