SequenceRange (Apache Derby V10.14 Internals)

java.lang.Object
- org.apache.derby.impl.sql.catalog.SequenceRange

All Implemented Interfaces:

SequencePreallocator
```
public class SequenceRange
extends java.lang.Object
implements SequencePreallocator
```
Default Derby logic for determining how many values to pre-allocate for an identity column or sequence.

Field Summary

Fields
Modifier and Type Field Description

private int _rangeSize

private static int DEFAULT_PREALLOCATION_COUNT
Default number of values to pre-allocate.

Constructor Summary

Constructors
Constructor Description

SequenceRange()
0-arg constructore needed to satisfy the SequencePreallocator contract.

SequenceRange(int rangeSize)

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`int`	`nextRangeSize(java.lang.String schemaName, java.lang.String sequenceName)`	This method returns the size of the next pre-allocated range for the specified sequence.

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

- Field Detail
  - DEFAULT_PREALLOCATION_COUNT
```
private static final int DEFAULT_PREALLOCATION_COUNT
```
    Default number of values to pre-allocate. Other databases use a preallocation size of 20 (see DERBY-4437). We boosted this to 100 in order to get better concurrency, after fixing correctness problems in pre-allocation (see DERBY-5493).
    
    See Also:
    
    Constant Field Values
  - _rangeSize
```
private int _rangeSize
```
- Constructor Detail
  - SequenceRange
```
public SequenceRange()
```
    0-arg constructore needed to satisfy the SequencePreallocator contract.
  - SequenceRange
```
public SequenceRange(int rangeSize)
```
- Method Detail
  - nextRangeSize
```
public int nextRangeSize(java.lang.String schemaName,
                         java.lang.String sequenceName)
```
    Description copied from interface: SequencePreallocator
    
    This method returns the size of the next pre-allocated range for the specified sequence. Names are case-sensitive, as specified in CREATE SEQUENCE and CREATE TABLE statements.
    
    Specified by:
    
    nextRangeSize in interface SequencePreallocator
    
    Parameters:
    
    schemaName - Name of schema holding the sequence.
    
    sequenceName - Specific name of the sequence.