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java.lang.Object | +--DSRG.VKB.Version
this class is needed to support the QC-Model. It contains a view definition, and a vector of suggestions for its rewriting after a certain schema change. Those suggestions are not materialized, but they have "QC-Values", which are objects of another new class, called "QC".
Field Summary | |
private static boolean |
DEBUG
|
private View_Definition |
definition
|
private MKB |
myMKB
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private View_Definition |
oldDefinition
|
private QC |
qcValues
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private double |
w_nonrepl
the tradeoff parameters for replaceable and non-replaceable attributes, this will not be in the QC-class. |
private double |
w_repl
the tradeoff parameters for replaceable and non-replaceable attributes, this will not be in the QC-class. |
Constructor Summary | |
Version(View_Definition myOldDefinition,
View_Definition myDefinition,
QC myQCValues,
MKB theMKB)
the constructor creates a version of a view. |
Method Summary | |
private long |
computeCF_IO()
compute number of I/O-operations. |
private long |
computeCF_M()
compute number of messages. |
private long |
computeCF_T()
Compute number of transferred bytes. We need to compute how many bytes are transferred between view site and ISs. |
private double |
computeDDattr()
compute DDattr from the View Definition |
private double |
computeDDext()
compute DDext from the ViewDefinitions. |
private double |
computeQV(View_Definition vd)
compute Q(V) --- the intermediate value needed to compute DD_attr |
java.lang.String |
getDefinition()
returns the (SQL-)definition of this version |
View_Definition |
getDefinitionAsObject()
returns the View_Definition object of this version |
View_Definition |
getOldDefinitionAsObject()
returns the View_Definition object of the old VD of this version |
QC |
getQC()
returns the QC-Object of this version |
private long |
viewSizeEstimate(View_Definition def)
private method to compute the number of tuples in a view (by multiplying selectivities and relation sizes |
Methods inherited from class java.lang.Object |
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Field Detail |
private static final boolean DEBUG
private View_Definition oldDefinition
private View_Definition definition
private QC qcValues
private double w_repl
private double w_nonrepl
private MKB myMKB
Constructor Detail |
public Version(View_Definition myOldDefinition, View_Definition myDefinition, QC myQCValues, MKB theMKB)
Method Detail |
private double computeDDattr()
private double computeQV(View_Definition vd)
private double computeDDext()
private long viewSizeEstimate(View_Definition def)
private long computeCF_M()
private long computeCF_T()
private long computeCF_IO()
public View_Definition getDefinitionAsObject()
public View_Definition getOldDefinitionAsObject()
public java.lang.String getDefinition()
public QC getQC()
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