org.hibernate.loader

Enum BatchFetchStyle

java.lang.Object

java.lang.Enum<BatchFetchStyle>

org.hibernate.loader.BatchFetchStyle

All Implemented Interfaces:

Serializable, Comparable<BatchFetchStyle>

public enum BatchFetchStyle
extends Enum<BatchFetchStyle>

Defines the style that should be used to perform batch loading. Which style to use is declared using the ""hibernate.batch_fetch_style"" (AvailableSettings.BATCH_FETCH_STYLE) setting

Author:

Steve Ebersole

Enum Constant Summary

Enum Constants

Enum Constant and Description
DYNAMIC Dynamically builds its SQL based on the actual number of available ids.
LEGACY The legacy algorithm where we keep a set of pre-built batch sizes based on ArrayHelper.getBatchSizes(int).
PADDED Still keeps the concept of pre-built batch sizes, but uses the next-bigger batch size and pads the extra identifier placeholders.

Method Summary

Methods

Modifier and Type	Method and Description
static BatchFetchStyle	byName(String name)
static BatchFetchStyle	interpret(Object setting)
static BatchFetchStyle	valueOf(String name) Returns the enum constant of this type with the specified name.
static BatchFetchStyle[]	values() Returns an array containing the constants of this enum type, in the order they are declared.

Methods inherited from class java.lang.Enum

clone, compareTo, equals, finalize, getDeclaringClass, hashCode, name, ordinal, toString, valueOf

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Enum Constant Detail

LEGACY

public static final BatchFetchStyle LEGACY

The legacy algorithm where we keep a set of pre-built batch sizes based on ArrayHelper.getBatchSizes(int). Batches are performed using the next-smaller pre-built batch size from the number of existing batchable identifiers.

For example, with a batch-size setting of 32 the pre-built batch sizes would be [32, 16, 10, 9, 8, 7, .., 1]. An attempt to batch load 31 identifiers would result in batches of 16, 10, and 5.

PADDED

public static final BatchFetchStyle PADDED

Still keeps the concept of pre-built batch sizes, but uses the next-bigger batch size and pads the extra identifier placeholders.

Using the same example of a batch-size setting of 32 the pre-built batch sizes would be the same. However, the attempt to batch load 31 identifiers would result just a single batch of size 32. The identifiers to load would be "padded" (aka, repeated) to make up the difference.

DYNAMIC

public static final BatchFetchStyle DYNAMIC

Dynamically builds its SQL based on the actual number of available ids. Does still limit to the batch-size defined on the entity/collection

Method Detail

values

public static BatchFetchStyle[] values()

Returns an array containing the constants of this enum type, in the order they are declared. This method may be used to iterate over the constants as follows:

for (BatchFetchStyle c : BatchFetchStyle.values())
    System.out.println(c);

Returns:

an array containing the constants of this enum type, in the order they are declared

valueOf

public static BatchFetchStyle valueOf(String name)

Returns the enum constant of this type with the specified name. The string must match exactly an identifier used to declare an enum constant in this type. (Extraneous whitespace characters are not permitted.)

Parameters:

name - the name of the enum constant to be returned.

Returns:

the enum constant with the specified name

Throws:

IllegalArgumentException - if this enum type has no constant with the specified name

NullPointerException - if the argument is null

byName

public static BatchFetchStyle byName(String name)

interpret

public static BatchFetchStyle interpret(Object setting)