net.sf.saffron.core
Interface SaffronTable

All Known Subinterfaces:

ImplementableTable

All Known Implementing Classes:

AbstractTable, JdbcTable

public interface SaffronTable

Represents a relational dataset in a SaffronSchema. It has methods to describe and implement itself.

Since:

10 November, 2001

Version:

$Id: //open/saffron/src/net/sf/saffron/core/SaffronTable.java#3 $

Author:

jhyde

Method Summary

String	getQualifiedName() Obtain an identifier for this table.
double	getRowCount() Returns an estimate of the number of rows in the table.
SaffronType	getRowType() Describes the type of rows returned by this table.
SaffronSchema	getSaffronSchema() Returns the SaffronSchema this table belongs to.
SaffronRel	toRel(VolcanoCluster cluster, SaffronConnection connection) Converts this table into a relational expression.

Method Detail

getQualifiedName

public String getQualifiedName()

Obtain an identifier for this table. The identifier must be unique with respect to the Connection producing this table.

Returns:

qualified name

getRowCount

public double getRowCount()

Returns an estimate of the number of rows in the table.

getRowType

public SaffronType getRowType()

Describes the type of rows returned by this table.

getSaffronSchema

public SaffronSchema getSaffronSchema()

Returns the SaffronSchema this table belongs to.

toRel

public SaffronRel toRel(VolcanoCluster cluster,
                        SaffronConnection connection)

Converts this table into a relational expression.

The planner calls this method to convert a table into an initial relational expression, generally something abstract, such as a TableAccessRel, then optimizes this expression by applying rules to transform it into more efficient access methods for this table.

Parameters:

cluster - the cluster the relational expression will belong to

connection - the parse tree of the expression which evaluates to a connection object

Pre-condition:

cluster != null, connection != null