Package org.apache.drill.exec.expr

Drill expression materialization and evaluation facilities.

See: Description

Interface Summary

Interface	Description
DrillAggFunc	Aggregate function interface.
DrillFunc
DrillSimpleFunc
FilterPredicate<T extends Comparable<T>>

Class Summary

Class	Description
AbstractExecExprVisitor<T,VAL,EXCEP extends Exception>
BasicTypeHelper
BatchReference	Holder class that contains batch naming, batch and record index.
BooleanPredicate<C extends Comparable<C>>
ClassGenerator<T>
ClassGenerator.HoldingContainer	Represents a (Nullable)?(Type)Holder instance.
CloneVisitor	Creates a deep copy of a LogicalExpression.
CodeGenerator<T>	A code generator is responsible for generating the Java source code required to complete the implementation of an abstract template.
ComparisonPredicate<C extends Comparable<C>>	Comparison predicates for metadata filter pushdown.
DebugStringBuilder	Utility class to build a debug string for an object in a standard format.
DirectExpression	Encapsulates a Java expression, defined as anything that is valid in the following code: (expr)
DrillFuncHolderExpr	Represents the call of a function within a query and includes the actual arguments and a reference to the function declaration (as a "function holder.")
EvaluationVisitor	Visitor that generates code for eval
EvaluationVisitor.VectorVariableHolder	Extended variable descriptor ("holding container") for the variable which references the value holder ("FooHolder") that stores the value from a value vector.
ExpressionTreeMaterializer
FilterBuilder	A visitor which visits a materialized logical expression, and build FilterPredicate If a visitXXX method returns null, that means the corresponding filter branch is not qualified for push down.
GetSetVectorHelper
HashVisitor
HiveFuncHolderExpr
HoldingContainerExpression	Wrapper around a representation of a "Holder" to represent that Holder as an expression.
IsPredicate<C extends Comparable<C>>
SingleClassStringWriter
SizedJBlock	Uses this class to keep track # of Drill Logical Expressions that are put to JBlock.
StatisticsProvider<T extends Comparable<T>>
TypeHelper
ValueVectorReadExpression	Wraps a value vector field to be read, providing metadata about the field.
ValueVectorWriteExpression

Enum Summary

Enum	Description
ClassGenerator.BlkCreateMode
ClassGenerator.BlockType

Package org.apache.drill.exec.expr Description

Drill expression materialization and evaluation facilities. Drill exposes an interface for defining custom scalar and aggregate functions. These functions are found by scanning the classpath at runtime and allow users to add their own functions without rebuilding Drill or changing cluster configuration. The classes that define these functions are actually decomposed at the source level, copied into generated code blocks to evaluate an entire expression tree. This generated source is built at run-time as schema is discovered. This package contains the DrillSimpleFunc and DrillAggFunc interfaces that can be implemented by users to define their own aggregate and scalar functions.