Package net.sf.saffron.rel

Defines Saffron relational expressions.


Interface Summary
Aggregation An Aggregation aggregates a set of values into one value.

Class Summary
AggregateRel AggregateRel is a relational operator which eliminates duplicates and computes totals.
CorrelatorRel A CorrelatorRel behaves like a kind of JoinRel, but works by setting variables in its environment and restarting its right-hand input.
DistinctRel DistinctRel is a SaffronRel which eliminates duplicates from its input.
FilterRel A FilterRel is a relational expression which iterates over its input, and returns elements for which condition evaluates to true.
IntersectRel todo:
JoinRel A JoinRel represents two relational expressions joined according to some condition.
JoinRel.JoinType Enumeration of join types.
MinusRel todo:
OneRowRel OneRowRel always returns one row, zero columns.
ProjectRel ProjectRel is a relational expression which computes a set of 'select expressions' from its input relational expression.
ProjectRelBase ProjectRelBase is an abstract base class for SaffronRels which perform projection.
RelFieldCollation RelFieldCollation defines the ordering for one field of a SaffronRel whose output is to be sorted.
RelVisitor A RelVisitor is a Visitor role in the Visitor pattern and visits SaffronRel objects as the role of Element.
RemoveDistinctRule Rule to remove a DistinctRel if the underlying relational expression is already distinct.
RemoveTrivialProjectRule Rule which, given a ProjectRel node which merely returns its input, converts the node into its child.
SaffronRel A SaffronRel is a relational expression.
SingleRel A SingleRel is a base class single-input relational expressions.
SortRel Relational expression which imposes a particular sort order on its input without otherwise changing its content.
SwapJoinRule SwapJoinRule permutes the inputs to a join.
SwapJoinRule.VariableReplacer Walks over an expression, replacing references to fields of the left and right inputs.
TableAccessRel A TableAccessRel reads all the rows from a SaffronTable.
TableModificationRel TableModificationRel is like TableAccessRel, but represents a request to modify a table rather than read from it.
TableModificationRel.Operation Enumeration of supported modification operations.
UnionRel UnionRel returns the union of the rows of its inputs, optionally eliminating duplicates.
UnionToDistinctRule UnionToDistinctRule translates a distinct UnionRel (all = false) into a DistinctRel on top of a non-distinct UnionRel (all = true).

Package net.sf.saffron.rel Description

Defines Saffron relational expressions.


Revision $Id: //open/saffron/src/net/sf/saffron/rel/package.html#3 $
Copyright (C) Copyright 2003-2003 Disruptive Technologies, Inc.
Author Julian Hyde

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