java.io.Externalizable
, java.io.Serializable
, Statistics
, Formatable
, TypedFormat
public class StatisticsImpl extends java.lang.Object implements Statistics, Formatable
Modifier and Type | Field | Description |
---|---|---|
private long |
numRows |
|
private long |
numUnique |
Constructor | Description |
---|---|
StatisticsImpl() |
Zero argument constructor for Formatable Interface
|
StatisticsImpl(long numRows,
long numUnique) |
Constructor for StatisticsImpl.
|
Modifier and Type | Method | Description |
---|---|---|
long |
getRowEstimate() |
Returns the estimated number of rows in the index.
|
int |
getTypeFormatId() |
Get a universally unique identifier for the type of
this object.
|
void |
readExternal(java.io.ObjectInput in) |
|
double |
selectivity(java.lang.Object[] predicates) |
|
java.lang.String |
toString() |
|
void |
writeExternal(java.io.ObjectOutput out) |
Write this object to a stream of stored objects.
|
public StatisticsImpl(long numRows, long numUnique)
numRows
- number of rows in the conglomerate for which
this statistic is being created.numUnique
- number of unique values in the key for which
this statistic is being created.public StatisticsImpl()
public long getRowEstimate()
getRowEstimate
in interface Statistics
public double selectivity(java.lang.Object[] predicates)
selectivity
in interface Statistics
Statistics.selectivity(java.lang.Object[])
public void readExternal(java.io.ObjectInput in) throws java.io.IOException, java.lang.ClassNotFoundException
readExternal
in interface java.io.Externalizable
java.io.IOException
java.lang.ClassNotFoundException
Externalizable.readExternal(java.io.ObjectInput)
public void writeExternal(java.io.ObjectOutput out) throws java.io.IOException
writeExternal
in interface java.io.Externalizable
out
- write bytes here.java.io.IOException
- thrown on errorpublic int getTypeFormatId()
TypedFormat
getTypeFormatId
in interface TypedFormat
public java.lang.String toString()
toString
in class java.lang.Object
Object.toString()
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