CoGaDB::SQL::ParseTree::BetweenPredicate Struct Reference

#include <sql_parsetree.hpp>

Inheritance diagram for CoGaDB::SQL::ParseTree::BetweenPredicate:

Collaboration diagram for CoGaDB::SQL::ParseTree::BetweenPredicate:

List of all members.

Public Member Functions
	BetweenPredicate (ScalarExpressionPtr _exp, ScalarExpressionPtr _lvalue, ScalarExpressionPtr _rvalue)
	Construct BETWEEN predicate.
KNF_Selection_Expression	getCNF (TypedNodePtr &io_node)
	Calculate CNF of a BETWEEN predicate.
Public Attributes
AndConditionPtr	and_cond

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Constructor & Destructor Documentation

CoGaDB::SQL::ParseTree::BetweenPredicate::BetweenPredicate	(	ScalarExpressionPtr	_exp,
		ScalarExpressionPtr	_lvalue,
		ScalarExpressionPtr	_rvalue
	)

Construct BETWEEN predicate.

Currently the BETWEEN predicate is implemented as a conjunction of to predicates using parse tree nodes. With CoGaDB's current set of supported predicate operators, this results in a CNF like "(exp = val1 OR exp > val1) AND (exp = val2 OR exp < val2)".

In the future, we might represent BETWEEN predicates as entirely distinct nodes with custom implementations of getCNF(). This would allow us to minimize the amount of logical query plan operators for algebraic operations in the predicate.

Parameters:

_exp	The value that should be checked
_lvalue	The lower inclusive value
_rvalue	The upper inclusive value

Returns:

A BETWEEN predicate node

References CoGaDB::GREATER_EQUAL, and CoGaDB::LESSER_EQUAL.

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Member Function Documentation

KNF_Selection_Expression CoGaDB::SQL::ParseTree::BetweenPredicate::getCNF

(

TypedNodePtr &

io_node

)

[virtual]

Calculate CNF of a BETWEEN predicate.

Implements CoGaDB::SQL::ParseTree::SearchCondition.

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Member Data Documentation

AndConditionPtr CoGaDB::SQL::ParseTree::BetweenPredicate::and_cond

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The documentation for this struct was generated from the following files:

• /home/sebastian/gpudbms/trunk/cogadb/include/sql/server/sql_parsetree.hpp
• /home/sebastian/gpudbms/trunk/cogadb/src/sql/server/sql_parsetree.cpp