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org.apache.derby.impl.store.access

public Class UTFQualifier

extends Object
implements Qualifier
Class Inheritance
All Implemented Interfaces
org.apache.derby.iapi.store.access.Qualifier
Imports
org.apache.derby.iapi.types.DataValueDescriptor, org.apache.derby.iapi.store.access.Qualifier

Field Summary

Modifier and TypeField and Description
private int
columnId

private UTF
value

Constructor Summary

AccessConstructor and Description
public
UTFQualifier(int columnId, String value)

Method Summary

Modifier and TypeMethod and Description
public void
clearOrderableCache()

Implements org.apache.derby.iapi.store.access.Qualifier.clearOrderableCache.

Clear the DataValueDescriptor cache, if one exists.

public int
getColumnId()

Implements org.apache.derby.iapi.store.access.Qualifier.getColumnId.

Get the id of the column to be qualified.

public int
getOperator()

Implements org.apache.derby.iapi.store.access.Qualifier.getOperator.

Get the operator to use in the comparison.

public DataValueDescriptor
getOrderable()

Implements org.apache.derby.iapi.store.access.Qualifier.getOrderable.

Get the value that the column is to be compared to.

public boolean
getOrderedNulls()

Implements org.apache.derby.iapi.store.access.Qualifier.getOrderedNulls.

Get the getOrderedNulls argument to use in the comparison.

public boolean
getUnknownRV()

Implements org.apache.derby.iapi.store.access.Qualifier.getUnknownRV.

Get the getOrderedNulls argument to use in the comparison.

public boolean
negateCompareResult()

Implements org.apache.derby.iapi.store.access.Qualifier.negateCompareResult.

Determine if the result from the compare operation is to be negated.

public void
reinitialize()

Implements org.apache.derby.iapi.store.access.Qualifier.reinitialize.

This method reinitializes all the state of the Qualifier.

Inherited from java.lang.Object:
cloneequalsfinalizegetClasshashCodenotifynotifyAlltoStringwaitwaitwait

Field Detail

columnIdback to summary
private int columnId
valueback to summary
private UTF value

Constructor Detail

UTFQualifierback to summary
public UTFQualifier(int columnId, String value)

Method Detail

clearOrderableCacheback to summary
public void clearOrderableCache()

Implements org.apache.derby.iapi.store.access.Qualifier.clearOrderableCache.

Clear the DataValueDescriptor cache, if one exists. (The DataValueDescriptor can be 1 of 3 types: o VARIANT - cannot be cached as its value can vary within a scan o SCAN_INVARIANT - can be cached within a scan as its value will not change within a scan o QUERY_INVARIANT- can be cached across the life of the query as its value will never change o CONSTANT - can be cached across executions

See Also
Qualifier#getUnknownRV
getColumnIdback to summary
public int getColumnId()

Implements org.apache.derby.iapi.store.access.Qualifier.getColumnId.

Get the id of the column to be qualified.

getOperatorback to summary
public int getOperator()

Implements org.apache.derby.iapi.store.access.Qualifier.getOperator.

Get the operator to use in the comparison.

See Also
DataValueDescriptor#compare
getOrderableback to summary
public DataValueDescriptor getOrderable()

Implements org.apache.derby.iapi.store.access.Qualifier.getOrderable.

Get the value that the column is to be compared to.

getOrderedNullsback to summary
public boolean getOrderedNulls()

Implements org.apache.derby.iapi.store.access.Qualifier.getOrderedNulls.

Doc from org.apache.derby.iapi.store.access.Qualifier.getOrderedNulls.

Get the getOrderedNulls argument to use in the comparison.

See Also
Qualifier#getOrderedNulls
getUnknownRVback to summary
public boolean getUnknownRV()

Implements org.apache.derby.iapi.store.access.Qualifier.getUnknownRV.

Get the getOrderedNulls argument to use in the comparison.

See Also
DataValueDescriptor#compare
negateCompareResultback to summary
public boolean negateCompareResult()

Implements org.apache.derby.iapi.store.access.Qualifier.negateCompareResult.

Determine if the result from the compare operation is to be negated.

If true then only rows which fail the compare operation will qualify.

See Also
DataValueDescriptor#compare
reinitializeback to summary
public void reinitialize()

Implements org.apache.derby.iapi.store.access.Qualifier.reinitialize.

This method reinitializes all the state of the Qualifier. It is used to distinguish between resetting something that is query invariant and something that is constant over every execution of a query. Basically, clearOrderableCache() will only clear out its cache if it is a VARIANT or SCAN_INVARIANT value. However, each time a query is executed, the QUERY_INVARIANT qualifiers need to be reset.