UTFQualifier (Apache Derby V10.14 Internals)

java.lang.Object
- org.apache.derby.impl.store.access.UTFQualifier

All Implemented Interfaces:: Qualifier

public class UTFQualifier
extends java.lang.Object
implements Qualifier

Field Summary

Fields
Modifier and Type Field Description

private int columnId

private UTF value
- Fields inherited from interface org.apache.derby.iapi.store.access.Qualifier
  CONSTANT, QUERY_INVARIANT, SCAN_INVARIANT, VARIANT

Fields
Modifier and Type	Field	Description
`private int`	`columnId`
`private UTF`	`value`

Constructor Summary

Constructors
Constructor Description

UTFQualifier(int columnId, java.lang.String value)

Constructors
Constructor	Description
`UTFQualifier(int columnId, java.lang.String value)`

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`void`	`clearOrderableCache()`	Clear the DataValueDescriptor cache, if one exists.
`int`	`getColumnId()`	Get the id of the column to be qualified.
`int`	`getOperator()`	Get the operator to use in the comparison.
`DataValueDescriptor`	`getOrderable()`	Get the value that the column is to be compared to.
`boolean`	`getOrderedNulls()`	Get the getOrderedNulls argument to use in the comparison.
`boolean`	`getUnknownRV()`	Get the getOrderedNulls argument to use in the comparison.
`boolean`	`negateCompareResult()`	Determine if the result from the compare operation is to be negated.
`void`	`reinitialize()`	This method reinitializes all the state of the Qualifier.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - value
```
private UTF value
```
  - columnId
```
private int columnId
```
- Constructor Detail
  - UTFQualifier
```
public UTFQualifier(int columnId,
                    java.lang.String value)
```
- Method Detail
  - getColumnId
```
public int getColumnId()
```
    Get the id of the column to be qualified.
    
    Specified by:
    
    getColumnId in interface Qualifier
  - getOrderable
```
public DataValueDescriptor getOrderable()
```
    Get the value that the column is to be compared to.
    
    Specified by:
    
    getOrderable in interface Qualifier
  - getOperator
```
public int getOperator()
```
    Get the operator to use in the comparison.
    
    Specified by:
    
    getOperator in interface Qualifier
    
    See Also:
    
    DataValueDescriptor.compare(org.apache.derby.iapi.types.DataValueDescriptor)
  - negateCompareResult
```
public boolean 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.
    
    Specified by:
    
    negateCompareResult in interface Qualifier
    
    See Also:
    
    DataValueDescriptor.compare(org.apache.derby.iapi.types.DataValueDescriptor)
  - getOrderedNulls
```
public boolean getOrderedNulls()
```
    Description copied from interface: Qualifier
    
    Get the getOrderedNulls argument to use in the comparison.
    
    Specified by:
    
    getOrderedNulls in interface Qualifier
    
    See Also:
    
    Qualifier.getOrderedNulls()
  - getUnknownRV
```
public boolean getUnknownRV()
```
    Get the getOrderedNulls argument to use in the comparison.
    
    Specified by:
    
    getUnknownRV in interface Qualifier
    
    See Also:
    
    DataValueDescriptor.compare(org.apache.derby.iapi.types.DataValueDescriptor)
  - clearOrderableCache
```
public void 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
    
    Specified by:
    
    clearOrderableCache in interface Qualifier
    
    See Also:
    
    Qualifier.getUnknownRV()
  - reinitialize
```
public void 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.
    
    Specified by:
    
    reinitialize in interface Qualifier

Class UTFQualifier

Field Summary

Fields inherited from interface org.apache.derby.iapi.store.access.Qualifier

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

value

columnId

Constructor Detail

UTFQualifier

Method Detail

getColumnId

getOrderable

getOperator

negateCompareResult

getOrderedNulls

getUnknownRV

clearOrderableCache

reinitialize