io.objectbox.annotation

Enum IndexType

java.lang.Object

java.lang.Enum<IndexType>

io.objectbox.annotation.IndexType

All Implemented Interfaces:

java.io.Serializable, java.lang.Comparable<IndexType>

public enum IndexType
extends java.lang.Enum<IndexType>

ObjectBox offers a value and two hash index types, from which it chooses a reasonable default (see DEFAULT).

For some queries/use cases it might make sense to override the default choice for optimization purposes.

Note: hash indexes are currently only supported for string properties.

Enum Constant Summary

Enum Constants

Enum Constant and Description
DEFAULT Use the default index type depending on the property type: VALUE for scalars and HASH for Strings.
HASH Use a (fast non-cryptographic) hash of the property value to build the index.
HASH64 Use a long (fast non-cryptographic) hash of the property value to build the index.
VALUE Use the property value to build the index.

Method Summary

Modifier and Type	Method and Description
static IndexType	valueOf(java.lang.String name) Returns the enum constant of this type with the specified name.
static IndexType[]	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

DEFAULT

public static final IndexType DEFAULT

Use the default index type depending on the property type: VALUE for scalars and HASH for Strings.

VALUE

public static final IndexType VALUE

Use the property value to build the index. For Strings this may occupy more space than the default setting.

HASH

public static final IndexType HASH

Use a (fast non-cryptographic) hash of the property value to build the index. Internally, it uses a 32 bit hash with a decent hash collision behavior. Because occasional collisions do not really impact performance, this is usually a better choice than HASH64 as it takes less space.

HASH64

public static final IndexType HASH64

Use a long (fast non-cryptographic) hash of the property value to build the index.

Method Detail

values

public static IndexType[] 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 (IndexType c : IndexType.values())
    System.out.println(c);

Returns:

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

valueOf

public static IndexType valueOf(java.lang.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:

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

java.lang.NullPointerException - if the argument is null