org.apache.phoenix.parse

Enum HintNode.Hint

java.lang.Object

java.lang.Enum<HintNode.Hint>

org.apache.phoenix.parse.HintNode.Hint

All Implemented Interfaces:

Serializable, Comparable<HintNode.Hint>

Enclosing class:

HintNode

public static enum HintNode.Hint
extends Enum<HintNode.Hint>

Enum Constant Summary

Enum Constants

Enum Constant and Description
INDEX Hint of the form INDEX( ...) to suggest usage of the index if possible.
NO_CACHE Avoid caching any HBase blocks loaded by this query.
NO_CHILD_PARENT_JOIN_OPTIMIZATION Prevents the usage of child-parent-join optimization.
NO_INDEX Prevents the usage of indexes, forcing usage of the data table for a query.
NO_SEEK_TO_COLUMN Avoid seeks to select specified columns.
NO_STAR_JOIN Avoid using star-join optimization.
RANGE_SCAN Forces a range scan to be used to process the query.
SEEK_TO_COLUMN Avoid using the no seek optimization.
SERIAL Enforces a serial scan.
SKIP_SCAN Forces a skip scan to be used to process the query.
SMALL Saves an RPC call on the scan.
USE_DATA_OVER_INDEX_TABLE All things being equal, use the data table instead of the index table when optimizing.
USE_INDEX_OVER_DATA_TABLE All things being equal, use the index table instead of the data table when optimizing.
USE_SORT_MERGE_JOIN Use sort-merge join algorithm instead of broadcast join (hash join) algorithm.

Method Summary

Methods

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

RANGE_SCAN

public static final HintNode.Hint RANGE_SCAN

Forces a range scan to be used to process the query.

SKIP_SCAN

public static final HintNode.Hint SKIP_SCAN

Forces a skip scan to be used to process the query.

NO_CHILD_PARENT_JOIN_OPTIMIZATION

public static final HintNode.Hint NO_CHILD_PARENT_JOIN_OPTIMIZATION

Prevents the usage of child-parent-join optimization.

NO_INDEX

public static final HintNode.Hint NO_INDEX

Prevents the usage of indexes, forcing usage of the data table for a query.

INDEX

public static final HintNode.Hint INDEX

Hint of the form INDEX( ...) to suggest usage of the index if possible. The first usable index in the list of indexes will be choosen. Table and index names may be surrounded by double quotes if they are case sensitive.

USE_DATA_OVER_INDEX_TABLE

public static final HintNode.Hint USE_DATA_OVER_INDEX_TABLE

All things being equal, use the data table instead of the index table when optimizing.

USE_INDEX_OVER_DATA_TABLE

public static final HintNode.Hint USE_INDEX_OVER_DATA_TABLE

All things being equal, use the index table instead of the data table when optimizing.

NO_CACHE

public static final HintNode.Hint NO_CACHE

Avoid caching any HBase blocks loaded by this query.

USE_SORT_MERGE_JOIN

public static final HintNode.Hint USE_SORT_MERGE_JOIN

Use sort-merge join algorithm instead of broadcast join (hash join) algorithm.

NO_STAR_JOIN

public static final HintNode.Hint NO_STAR_JOIN

Avoid using star-join optimization. Used for broadcast join (hash join) only.

SEEK_TO_COLUMN

public static final HintNode.Hint SEEK_TO_COLUMN

Avoid using the no seek optimization. When there are many columns which are not selected coming in between 2 selected columns and/or versions of columns, this should be used.

NO_SEEK_TO_COLUMN

public static final HintNode.Hint NO_SEEK_TO_COLUMN

Avoid seeks to select specified columns. When there are very less number of columns which are not selected in between 2 selected columns this will be give better performance.

SMALL

public static final HintNode.Hint SMALL

Saves an RPC call on the scan. See Scan.setSmall(true) in HBase documentation.

SERIAL

public static final HintNode.Hint SERIAL

Enforces a serial scan.

Method Detail

values

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

Returns:

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

valueOf

public static HintNode.Hint 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