org.apache.druid.segment.virtual

Class ExpressionPlan

java.lang.Object

org.apache.druid.segment.virtual.ExpressionPlan

public class ExpressionPlan
extends Object

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	ExpressionPlan.Trait

Method Summary

Modifier and Type	Method and Description
boolean	any(ExpressionPlan.Trait... flags) Returns true if any of the supplied traits are true in this plan
Expr.BindingAnalysis	getAnalysis() Returns basic analysis of the inputs to an Expr and how they are used
Expr	getAppliedExpression() If an expression uses a multi-valued input in a scalar manner, the expression can be automatically transformed to map these values across the expression, applying the original expression to every value.
Expr	getAppliedFoldExpression(String accumulatorId) If an expression uses a multi-valued input in a scalar manner, and the expression contains an accumulator such as for use as part of an aggregator, the expression can be automatically transformed to fold the accumulator across the values of the original expression.
Expr	getExpression() Gets the original expression that was planned
ExpressionType	getOutputType() The output type of the original expression.
String	getSingleInputName() If and only if the expression has a single input, get the name of that input
ColumnType	getSingleInputType() If and only if the column has a single input, get the ValueType of that input
Set<String>	getUnknownInputs() Get set of inputs which were completely missing information, possibly a non-existent column or from a column selector factory with incomplete information
ColumnCapabilities	inferColumnCapabilities(ColumnType outputTypeHint) Tries to construct the most appropriate ColumnCapabilities for this plan given the outputType and traits inferred by the ExpressionPlanner, optionally with the help of hint ValueType.
boolean	is(ExpressionPlan.Trait... flags) Returns true if all of the supplied traits are true in this plan
boolean	isConstant() An expression with no inputs is a constant

Methods inherited from class java.lang.Object

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

Method Detail

isConstant

public boolean isConstant()

An expression with no inputs is a constant

getExpression

public Expr getExpression()

Gets the original expression that was planned

getAppliedExpression

public Expr getAppliedExpression()

If an expression uses a multi-valued input in a scalar manner, the expression can be automatically transformed to map these values across the expression, applying the original expression to every value.

See Also:

Parser.applyUnappliedBindings(Expr, Expr.BindingAnalysis, List)

getAppliedFoldExpression

public Expr getAppliedFoldExpression(String accumulatorId)

If an expression uses a multi-valued input in a scalar manner, and the expression contains an accumulator such as for use as part of an aggregator, the expression can be automatically transformed to fold the accumulator across the values of the original expression.

See Also:

Parser.foldUnappliedBindings(Expr, Expr.BindingAnalysis, List, String)

getOutputType

@Nullable
public ExpressionType getOutputType()

The output type of the original expression. Note that this might not be the true for the expressions provided by getAppliedExpression() or getAppliedFoldExpression(String), should the expression have any unapplied inputs

getSingleInputType

@Nullable
public ColumnType getSingleInputType()

If and only if the column has a single input, get the ValueType of that input

getSingleInputName

public String getSingleInputName()

If and only if the expression has a single input, get the name of that input

getUnknownInputs

public Set<String> getUnknownInputs()

Get set of inputs which were completely missing information, possibly a non-existent column or from a column selector factory with incomplete information

getAnalysis

public Expr.BindingAnalysis getAnalysis()

Returns basic analysis of the inputs to an Expr and how they are used

See Also:

Expr.BindingAnalysis

inferColumnCapabilities

@Nullable
public ColumnCapabilities inferColumnCapabilities(@Nullable
                                                            ColumnType outputTypeHint)

Tries to construct the most appropriate ColumnCapabilities for this plan given the outputType and traits inferred by the ExpressionPlanner, optionally with the help of hint ValueType. If no output type was able to be inferred during planning, returns null

is

public boolean is(ExpressionPlan.Trait... flags)

Returns true if all of the supplied traits are true in this plan

any

public boolean any(ExpressionPlan.Trait... flags)

Returns true if any of the supplied traits are true in this plan