com.bigdata.bop.solutions

Interface IGroupByRewriteState

All Known Implementing Classes:

GroupByRewriter

public interface IGroupByRewriteState

A rewrite of a GroupByState in which all IAggregate expressions have been lifted out in order to (a) minimize redundancy when computing the aggregates; and (b) simplify the logic required to compute the IAggregates.

Version:

$Id$

Author:

Bryan Thompson

Method Summary

Methods

Modifier and Type	Method and Description
LinkedHashMap<IAggregate<?>,IVariable<?>>	getAggExpr() The set of all unique IAggregate expressions paired with anonymous variables.
IConstraint[]	getHaving2() A modified version of the original HAVING expression which has the same semantics (and null iff the original was null or empty).
IValueExpression<?>[]	getSelect2() A modified version of the original SELECT expression which has the same semantics.

Method Detail

getAggExpr

LinkedHashMap<IAggregate<?>,IVariable<?>> getAggExpr()

The set of all unique IAggregate expressions paired with anonymous variables. Any internal IAggregate have been lifted out and will appear before any IAggregates which use them. The IAggregate MAY have a complex internal IValueExpression, but it WILL NOT have a nested IAggregate.

getHaving2

IConstraint[] getHaving2()

A modified version of the original HAVING expression which has the same semantics (and null iff the original was null or empty). However, the modified select expressions DO NOT contain any IAggregate functions. All IAggregate functions have been lifted out into #aggExp.

getSelect2

IValueExpression<?>[] getSelect2()

A modified version of the original SELECT expression which has the same semantics. However, the modified select expressions DO NOT contain any IAggregate functions. All IAggregate functions have been lifted out into #aggExp.