Interface XPLAINFactoryIF

All Known Implementing Classes:
XPLAINFactory

public interface XPLAINFactoryIF
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

    Fields
    Modifier and Type
    Field
    Description
    static final String
    Module name for the monitor's module locating system.
  • Method Summary

    Modifier and Type
    Method
    Description
    void
    This method gets called when the user switches off the explain facility.
    This method returns an appropriate visitor to traverse the ResultSetStatistics.
  • Field Details

  • Method Details

    • getXPLAINVisitor

      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:
      a XPLAINVisitor to traverse the ResultSetStatistics
      Throws:
      StandardException
      See Also:
    • freeResources

      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.