org.eigenbase.relopt
Interface RelOptConnection

All Known Implementing Classes:

FarragoPreparingStmt, FarragoRuntimeContext, LucidDbPreparingStmt, LucidDbRuntimeContext, SqlToRelTestBase.MockRelOptConnection

public interface RelOptConnection

The planner's view of a connection to a database.

A connection contains a RelOptSchema, via which the query planner can access RelOptTable objects.

If used in saffron, and if saffron is being used as a Java preprocessor, then every class which implements RelOptConnection must implement the method

public static RelOptSchema getRelOptSchema()

Since:

10 November, 2001

Version:

$Id: //open/dev/farrago/src/org/eigenbase/relopt/RelOptConnection.java#10 $

Author:

jhyde

Method Summary

Object	contentsAsArray(String qualifier, String tableName) In theory, this method returns the contents of tableName as an array; in practice, it is a placeholder recognized by the optimizer to do something much more efficient.
RelOptSchema	getRelOptSchema() Returns the schema underlying this connection.

Method Detail

getRelOptSchema

RelOptSchema getRelOptSchema()

Returns the schema underlying this connection. Non-abstract classes implementing this interface must also provide public static Schema getRelOptSchemaStatic().

contentsAsArray

Object contentsAsArray(String qualifier,
                       String tableName)

In theory, this method returns the contents of tableName as an array; in practice, it is a placeholder recognized by the optimizer to do something much more efficient. This involves calling RelOptSchema.getTableForMember(java.lang.String[])(qualifier,tableName).RelOptTable.toRel(org.eigenbase.relopt.RelOptCluster, org.eigenbase.relopt.RelOptConnection)(cluster, exp).