Top Description Fields Methods
org.apache.derby.iapi.sql.execute.xplain

public Interface XPLAINFactoryIF

Known Direct Implementers
org.apache.derby.impl.sql.execute.xplain.XPLAINFactory
Imports
org.apache.derby.shared.common.error.StandardException
This is the factory interface of the XPLAINFactory facility. It extends the possibilities and provides a convenient protocol to explain queries on basis of the query execution plan. This plan manfifests in Derby in the different ResultSets and their associated statistics. The introduction of this factory interface makes it possible to switch to another implementation or to easily extend the API.

Field Summary

Modifier and TypeField and Description
public static final String
MODULE

Module name for the monitor's module locating system.

Method Summary

Modifier and TypeMethod and Description
public void
freeResources()

This method gets called when the user switches off the explain facility.

public XPLAINVisitor

Returns:

a XPLAINVisitor to traverse the ResultSetStatistics
getXPLAINVisitor()

This method returns an appropriate visitor to traverse the ResultSetStatistics.

Field Detail

MODULEback to summary
public static final String MODULE

Module name for the monitor's module locating system.

Method Detail

freeResourcesback to summary
public void freeResources()

This method gets called when the user switches off the explain facility. The factory destroys for example the cached visitor implementation(s) or releases resources to save memory.

getXPLAINVisitorback to summary
public XPLAINVisitor getXPLAINVisitor() throws StandardException

This method returns an appropriate visitor to traverse the ResultSetStatistics. Depending on the current configuration, the perfect visitor will be chosen, created and cached by this factory method.

Returns:XPLAINVisitor

a XPLAINVisitor to traverse the ResultSetStatistics

See Also
XPLAINVisitor