IndexDescriptorImpl (Apache Derby V10.10 Internals)

java.lang.Object
- org.apache.derby.catalog.types.IndexDescriptorImpl

All Implemented Interfaces:

java.io.Externalizable, java.io.Serializable, IndexDescriptor, Formatable, TypedFormat
```
public class IndexDescriptorImpl
extends java.lang.Object
implements IndexDescriptor, Formatable
```
See Also:

IndexRowGenerator, Serialized Form

Field Summary

Fields
Modifier and Type	Field and Description
`private int[]`	`baseColumnPositions`
`private java.lang.String`	`indexType`
`private boolean[]`	`isAscending`
`private boolean`	`isUnique` This class implements Formatable.
`private boolean`	`isUniqueWithDuplicateNulls`
`private int`	`numberOfOrderedColumns`

Constructor Summary

Constructors
Constructor and Description
`IndexDescriptorImpl()` Zero-argument constructor for Formatable interface
`IndexDescriptorImpl(java.lang.String indexType, boolean isUnique, boolean isUniqueWithDuplicateNulls, int[] baseColumnPositions, boolean[] isAscending, int numberOfOrderedColumns)` Constructor for an IndexDescriptorImpl

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`int[]`	`baseColumnPositions()` Returns an array of column positions in the base table.
`boolean`	`equals(java.lang.Object other)` Test for value equality
`int`	`getKeyColumnPosition(int heapColumnPosition)` Returns the postion of a column.
`int`	`getTypeFormatId()` Get a universally unique identifier for the type of this object.
`int`	`hashCode()`
`java.lang.String`	`indexType()` Returns the type of the index.
`boolean[]`	`isAscending()` Returns array of boolean telling asc/desc info for each index key column for convenience of using together with baseColumnPositions method.
`boolean`	`isAscending(java.lang.Integer keyColumnPosition)` Returns true if the specified column is ascending in the index (1-based).
`boolean`	`isDescending(java.lang.Integer keyColumnPosition)` Returns true if the specified column is descending in the index (1-based).
`boolean`	`isUnique()` Returns true if the index is unique.
`boolean`	`isUniqueWithDuplicateNulls()` Returns true if the index is duplicate keys only for null key parts.
`int`	`numberOfOrderedColumns()` Returns the number of ordered columns.
`void`	`readExternal(java.io.ObjectInput in)`
`void`	`setBaseColumnPositions(int[] baseColumnPositions)` set the baseColumnPositions field of the index descriptor.
`void`	`setIsAscending(boolean[] isAscending)` set the isAscending field of the index descriptor.
`void`	`setNumberOfOrderedColumns(int numberOfOrderedColumns)` set the numberOfOrderedColumns field of the index descriptor.
`java.lang.String`	`toString()`
`void`	`writeExternal(java.io.ObjectOutput out)`

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

- Field Detail
  - isUnique
```
private boolean isUnique
```
    This class implements Formatable. That means that it can write itself to and from a formatted stream. If you add more fields to this class, make sure that you also write/read them with the writeExternal()/readExternal() methods. If, inbetween releases, you add more fields to this class, then you should bump the version number emitted by the getTypeFormatId() method.
  - baseColumnPositions
```
private int[] baseColumnPositions
```
  - isAscending
```
private boolean[] isAscending
```
  - numberOfOrderedColumns
```
private int numberOfOrderedColumns
```
  - indexType
```
private java.lang.String indexType
```
  - isUniqueWithDuplicateNulls
```
private boolean isUniqueWithDuplicateNulls
```
- Constructor Detail
  - IndexDescriptorImpl
```
public IndexDescriptorImpl(java.lang.String indexType,
                           boolean isUnique,
                           boolean isUniqueWithDuplicateNulls,
                           int[] baseColumnPositions,
                           boolean[] isAscending,
                           int numberOfOrderedColumns)
```
    Constructor for an IndexDescriptorImpl
    
    Parameters:
    
    indexType - The type of index
    
    isUnique - True means the index is unique
    
    isUniqueWithDuplicateNulls - True means the index will be unique for non null values but duplicate nulls will be allowed. This parameter has no effect if the isUnique is true. If isUnique is false and isUniqueWithDuplicateNulls is set to true the index will allow duplicate nulls but for non null keys will act like a unique index.
    
    baseColumnPositions - An array of column positions in the base table. Each index column corresponds to a column position in the base table.
    
    isAscending - An array of booleans telling asc/desc on each column.
    
    numberOfOrderedColumns - In the future, it will be possible to store non-ordered columns in an index. These will be useful for covered queries.
  - IndexDescriptorImpl
```
public IndexDescriptorImpl()
```
    Zero-argument constructor for Formatable interface
- Method Detail
  - isUniqueWithDuplicateNulls
```
public boolean isUniqueWithDuplicateNulls()
```
    Description copied from interface: IndexDescriptor
    
    Returns true if the index is duplicate keys only for null key parts. This is effective only if isUnique is false.
    
    Specified by:
    
    isUniqueWithDuplicateNulls in interface IndexDescriptor
    
    See Also:
    
    IndexDescriptor.isUniqueWithDuplicateNulls()
  - isUnique
```
public boolean isUnique()
```
    Description copied from interface: IndexDescriptor
    
    Returns true if the index is unique.
    
    Specified by:
    
    isUnique in interface IndexDescriptor
    
    See Also:
    
    IndexDescriptor.isUnique()
  - baseColumnPositions
```
public int[] baseColumnPositions()
```
    Description copied from interface: IndexDescriptor
    
    Returns an array of column positions in the base table. Each index column corresponds to a column position in the base table, except the column representing the location of the row in the base table. The returned array holds the column positions in the base table, so, if entry 2 is the number 4, the second column in the index is the fourth column in the table.
    
    Specified by:
    
    baseColumnPositions in interface IndexDescriptor
    
    See Also:
    
    IndexDescriptor.baseColumnPositions()
  - getKeyColumnPosition
```
public int getKeyColumnPosition(int heapColumnPosition)
```
    Description copied from interface: IndexDescriptor
    
    Returns the postion of a column.
    Returns the position of a column within the key (1-based). 0 means that the column is not in the key. Same as the above method, but it uses int instead of Integer.
    
    Specified by:
    
    getKeyColumnPosition in interface IndexDescriptor
    
    See Also:
    
    IndexDescriptor.getKeyColumnPosition(int)
  - numberOfOrderedColumns
```
public int numberOfOrderedColumns()
```
    Description copied from interface: IndexDescriptor
    
    Returns the number of ordered columns.
    In the future, it will be possible to store non-ordered columns in an index. These will be useful for covered queries. The ordered columns will be at the beginning of the index row, and they will be followed by the non-ordered columns. For now, all columns in an index must be ordered.
    
    Specified by:
    
    numberOfOrderedColumns in interface IndexDescriptor
    
    See Also:
    
    IndexDescriptor.numberOfOrderedColumns()
  - indexType
```
public java.lang.String indexType()
```
    Description copied from interface: IndexDescriptor
    
    Returns the type of the index. For now, we only support B-Trees, so the value "BTREE" is returned.
    
    Specified by:
    
    indexType in interface IndexDescriptor
    
    See Also:
    
    IndexDescriptor.indexType()
  - isAscending
```
public boolean isAscending(java.lang.Integer keyColumnPosition)
```
    Description copied from interface: IndexDescriptor
    
    Returns true if the specified column is ascending in the index (1-based).
    
    Specified by:
    
    isAscending in interface IndexDescriptor
    
    See Also:
    
    IndexDescriptor.isAscending()
  - isDescending
```
public boolean isDescending(java.lang.Integer keyColumnPosition)
```
    Description copied from interface: IndexDescriptor
    
    Returns true if the specified column is descending in the index (1-based). In the current release, only ascending columns are supported.
    
    Specified by:
    
    isDescending in interface IndexDescriptor
    
    See Also:
    
    IndexDescriptor.isDescending(java.lang.Integer)
  - isAscending
```
public boolean[] isAscending()
```
    Description copied from interface: IndexDescriptor
    
    Returns array of boolean telling asc/desc info for each index key column for convenience of using together with baseColumnPositions method. Both methods return an array with subscript starting from 0.
    
    Specified by:
    
    isAscending in interface IndexDescriptor
    
    See Also:
    
    IndexDescriptor.isAscending()
  - setBaseColumnPositions
```
public void setBaseColumnPositions(int[] baseColumnPositions)
```
    Description copied from interface: IndexDescriptor
    
    set the baseColumnPositions field of the index descriptor. This is for updating the field in operations such as "alter table drop column" where baseColumnPositions is changed.
    
    Specified by:
    
    setBaseColumnPositions in interface IndexDescriptor
    
    See Also:
    
    IndexDescriptor.setBaseColumnPositions(int[])
  - setIsAscending
```
public void setIsAscending(boolean[] isAscending)
```
    Description copied from interface: IndexDescriptor
    
    set the isAscending field of the index descriptor. This is for updating the field in operations such as "alter table drop column" where isAscending is changed.
    
    Specified by:
    
    setIsAscending in interface IndexDescriptor
    
    See Also:
    
    IndexDescriptor.setIsAscending(boolean[])
  - setNumberOfOrderedColumns
```
public void setNumberOfOrderedColumns(int numberOfOrderedColumns)
```
    Description copied from interface: IndexDescriptor
    
    set the numberOfOrderedColumns field of the index descriptor. This is for updating the field in operations such as "alter table drop column" where numberOfOrderedColumns is changed.
    
    Specified by:
    
    setNumberOfOrderedColumns in interface IndexDescriptor
    
    See Also:
    
    IndexDescriptor.setNumberOfOrderedColumns(int)
  - toString
```
public java.lang.String toString()
```
    Overrides:
    
    toString in class java.lang.Object
  - readExternal
```
public void readExternal(java.io.ObjectInput in)
                  throws java.io.IOException,
                         java.lang.ClassNotFoundException
```
    Specified by:
    
    readExternal in interface java.io.Externalizable
    
    Throws:
    
    java.io.IOException - Thrown on read error
    
    java.lang.ClassNotFoundException
    
    See Also:
    
    Externalizable.readExternal(java.io.ObjectInput)
  - writeExternal
```
public void writeExternal(java.io.ObjectOutput out)
                   throws java.io.IOException
```
    Specified by:
    
    writeExternal in interface java.io.Externalizable
    
    Throws:
    
    java.io.IOException - Thrown on write error
    
    See Also:
    
    Externalizable.writeExternal(java.io.ObjectOutput)
  - getTypeFormatId
```
public int getTypeFormatId()
```
    Description copied from interface: TypedFormat
    
    Get a universally unique identifier for the type of this object.
    
    Specified by:
    
    getTypeFormatId in interface TypedFormat
    
    Returns:
    
    The identifier. (A UUID stuffed in an array of 16 bytes).
  - equals
```
public boolean equals(java.lang.Object other)
```
    Test for value equality
    
    Overrides:
    
    equals in class java.lang.Object
    
    Parameters:
    
    other - The other indexrowgenerator to compare this one with
    
    Returns:
    
    true if this indexrowgenerator has the same value as other
  - hashCode
```
public int hashCode()
```
    Overrides:
    
    hashCode in class java.lang.Object
    
    See Also:
    
    Object.hashCode()

Class IndexDescriptorImpl

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

isUnique

baseColumnPositions

isAscending

numberOfOrderedColumns

indexType

isUniqueWithDuplicateNulls

Constructor Detail

IndexDescriptorImpl

IndexDescriptorImpl

Method Detail

isUniqueWithDuplicateNulls

isUnique

baseColumnPositions

getKeyColumnPosition

numberOfOrderedColumns

indexType

isAscending

isDescending

isAscending

setBaseColumnPositions

setIsAscending

setNumberOfOrderedColumns

toString

readExternal

writeExternal

getTypeFormatId

equals

hashCode