org.apache.iceberg.expressions

Class ResidualEvaluator

java.lang.Object

org.apache.iceberg.expressions.ResidualEvaluator

All Implemented Interfaces:

java.io.Serializable

public class ResidualEvaluator
extends java.lang.Object
implements java.io.Serializable

Finds the residuals for an Expression the partitions in the given PartitionSpec.

A residual expression is made by partially evaluating an expression using partition values. For example, if a table is partitioned by day(utc_timestamp) and is read with a filter expression utc_timestamp >= a and utc_timestamp <= b, then there are 4 possible residuals expressions for the partition data, d:

• If d > day(a) and d < day(b), the residual is always true
• If d == day(a) and d != day(b), the residual is utc_timestamp >= a
• if d == day(b) and d != day(a), the residual is utc_timestamp <= b
• If d == day(a) == day(b), the residual is utc_timestamp >= a and utc_timestamp <= b

Partition data is passed using StructLike. Residuals are returned by residualFor(StructLike).

This class is thread-safe.

See Also:

Serialized Form

Method Summary

Modifier and Type	Method and Description
static ResidualEvaluator	of(PartitionSpec spec, Expression expr, boolean caseSensitive) Return a residual evaluator for a spec and expression.
Expression	residualFor(StructLike partitionData) Returns a residual expression for the given partition values.
static ResidualEvaluator	unpartitioned(Expression expr) Return a residual evaluator for an unpartitioned spec.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

unpartitioned

public static ResidualEvaluator unpartitioned(Expression expr)

Return a residual evaluator for an unpartitioned spec.

Parameters:

expr - an expression

Returns:

a residual evaluator that always returns the expression

of

public static ResidualEvaluator of(PartitionSpec spec,
                                   Expression expr,
                                   boolean caseSensitive)

Return a residual evaluator for a spec and expression.

Parameters:

spec - a partition spec

expr - an expression

Returns:

a residual evaluator for the expression

residualFor

public Expression residualFor(StructLike partitionData)

Returns a residual expression for the given partition values.

Parameters:

partitionData - partition data values

Returns:

the residual of this evaluator's expression from the partition values