org.apache.calcite.sql.validate

Enum SqlMonotonicity

java.lang.Object

java.lang.Enum<SqlMonotonicity>

org.apache.calcite.sql.validate.SqlMonotonicity

All Implemented Interfaces:

Serializable, Comparable<SqlMonotonicity>

public enum SqlMonotonicity
extends Enum<SqlMonotonicity>

Enumeration of types of monotonicity.

Enum Constant Summary

Enum Constants

Enum Constant and Description
CONSTANT
DECREASING
INCREASING
MONOTONIC Catch-all value for expressions that have some monotonic properties.
NOT_MONOTONIC
STRICTLY_DECREASING
STRICTLY_INCREASING

Method Summary

Methods

Modifier and Type	Method and Description
boolean	isDecreasing() Whether values of this monotonicity are decreasing.
boolean	mayRepeat() Returns whether values of this monotonicity may ever repeat after moving to another value: true for NOT_MONOTONIC and CONSTANT, false otherwise.
SqlMonotonicity	reverse() Returns the reverse monotonicity.
SqlMonotonicity	unstrict() If this is a strict monotonicity (StrictlyIncreasing, StrictlyDecreasing) returns the non-strict equivalent (Increasing, Decreasing).
static SqlMonotonicity	valueOf(String name) Returns the enum constant of this type with the specified name.
static SqlMonotonicity[]	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

STRICTLY_INCREASING

public static final SqlMonotonicity STRICTLY_INCREASING

INCREASING

public static final SqlMonotonicity INCREASING

STRICTLY_DECREASING

public static final SqlMonotonicity STRICTLY_DECREASING

DECREASING

public static final SqlMonotonicity DECREASING

CONSTANT

public static final SqlMonotonicity CONSTANT

MONOTONIC

public static final SqlMonotonicity MONOTONIC

Catch-all value for expressions that have some monotonic properties. Maybe it isn't known whether the expression is increasing or decreasing; or maybe the value is neither increasing nor decreasing but the value never repeats.

NOT_MONOTONIC

public static final SqlMonotonicity NOT_MONOTONIC

Method Detail

values

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

Returns:

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

valueOf

public static SqlMonotonicity 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

unstrict

public SqlMonotonicity unstrict()

If this is a strict monotonicity (StrictlyIncreasing, StrictlyDecreasing) returns the non-strict equivalent (Increasing, Decreasing).

Returns:

non-strict equivalent monotonicity

reverse

public SqlMonotonicity reverse()

Returns the reverse monotonicity.

Returns:

reverse monotonicity

isDecreasing

public boolean isDecreasing()

Whether values of this monotonicity are decreasing. That is, if a value at a given point in a sequence is X, no point later in the sequence will have a value greater than X.

Returns:

whether values are decreasing

mayRepeat

public boolean mayRepeat()

Returns whether values of this monotonicity may ever repeat after moving to another value: true for NOT_MONOTONIC and CONSTANT, false otherwise.

If a column is known not to repeat, a sort on that column can make progress before all of the input has been seen.

Returns:

whether values repeat