com.apple.foundationdb.record.query.plan

Enum QueryPlanner.IndexScanPreference

java.lang.Object

java.lang.Enum<QueryPlanner.IndexScanPreference>

com.apple.foundationdb.record.query.plan.QueryPlanner.IndexScanPreference

All Implemented Interfaces:

Serializable, Comparable<QueryPlanner.IndexScanPreference>

Enclosing interface:

QueryPlanner

public static enum QueryPlanner.IndexScanPreference
extends Enum<QueryPlanner.IndexScanPreference>

Preference between index scan and record scan.

See Also:

QueryPlanner.setIndexScanPreference(com.apple.foundationdb.record.query.plan.QueryPlanner.IndexScanPreference)

Enum Constant Summary

Enum Constants

Enum Constant and Description
PREFER_INDEX Prefer index scan over full scan.
PREFER_PRIMARY_KEY_INDEX Prefer a scan using an index for exactly the primary key.
PREFER_SCAN Prefer a full scan over an index scan.

Method Summary

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

PREFER_SCAN

public static final QueryPlanner.IndexScanPreference PREFER_SCAN

Prefer a full scan over an index scan. A full scan does not have to separately fetch the record, but may return records of types that just need to be skipped.

PREFER_INDEX

public static final QueryPlanner.IndexScanPreference PREFER_INDEX

Prefer index scan over full scan. An index scan always fetches the record separately but is less vulnerable to the addition of records of unrelated record types.

PREFER_PRIMARY_KEY_INDEX

public static final QueryPlanner.IndexScanPreference PREFER_PRIMARY_KEY_INDEX

Prefer a scan using an index for exactly the primary key.

Method Detail

values

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

Returns:

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

valueOf

public static QueryPlanner.IndexScanPreference 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