net.sf.farrago.namespace
Interface FarragoMedDataServer

All Superinterfaces:

ClosableAllocation, FarragoAllocation

All Known Subinterfaces:

FarragoMedLocalDataServer

All Known Implementing Classes:

FlatFileDataServer, FtrsDataServer, LcsDataServer, MedAbstractDataServer, MedAbstractFennelDataServer, MedAbstractLocalDataServer, MedJdbcDataServer, MedMdrDataServer, MedMockDataServer, MedMockLocalDataServer, MedMqlDataServer

public interface FarragoMedDataServer
extends FarragoAllocation

FarragoMedDataServer defines an interface representing a server instance accessed via a FarragoMedDataWrapper.

Version:

$Id: //open/dev/farrago/src/net/sf/farrago/namespace/FarragoMedDataServer.java#18 $

Author:

John V. Sichi

Field Summary

static String	PROP_SERVER_NAME keyword for NAME in server properties list
static String	PROP_SERVER_TYPE keyword for TYPE in server properties list
static String	PROP_SERVER_VERSION keyword for VERSION in server properties list

Method Summary

FarragoMedNameDirectory	getNameDirectory() Gets a FarragoMedNameDirectory corresponding to this server.
Object	getRuntimeSupport(Object param) Gets an object needed for runtime support.
FarragoMedColumnSet	newColumnSet(String[] localName, Properties tableProps, FarragoTypeFactory typeFactory, RelDataType rowType, Map<String,Properties> columnPropMap) Creates an instance of a FarragoMedColumnSet corresponding to row data identified by properties rather than container name.
void	registerRelMetadataProviders(ChainedRelMetadataProvider chain) Gives this wrapper a chance to register one or more RelMetadataProviders in the chain which will be used to answer relational expression metadata queries during optimization.
void	registerRules(RelOptPlanner planner) Gives this wrapper a chance to register any special optimization rules.
void	releaseResources() Gives this wrapper a chance to release any resources.
void	setLoopbackDataSource(DataSource loopbackDataSource) Sets a loopback DataSource which can be used to issue internal SQL queries against the containing DBMS.

Methods inherited from interface org.eigenbase.util.ClosableAllocation

closeAllocation

Field Detail

PROP_SERVER_TYPE

static final String PROP_SERVER_TYPE

keyword for TYPE in server properties list

See Also:

Constant Field Values

PROP_SERVER_VERSION

static final String PROP_SERVER_VERSION

keyword for VERSION in server properties list

See Also:

Constant Field Values

PROP_SERVER_NAME

static final String PROP_SERVER_NAME

keyword for NAME in server properties list

See Also:

Constant Field Values

Method Detail

setLoopbackDataSource

void setLoopbackDataSource(DataSource loopbackDataSource)

Sets a loopback DataSource which can be used to issue internal SQL queries against the containing DBMS. This may be called multiple times on the same server instance with different data sources; the server should use only the last one provided.

Parameters:

loopbackDataSource - a DataSource for establishing a loopback connection into Farrago, or null if loopback connections are not available in the current context

getNameDirectory

FarragoMedNameDirectory getNameDirectory()
                                         throws SQLException

Gets a FarragoMedNameDirectory corresponding to this server.

Returns:

directory, or null if this server does not have the required metadata capability

Throws:

SQLException - if directory access is unsuccessful (but not if directory access is unsupported)

newColumnSet

FarragoMedColumnSet newColumnSet(String[] localName,
                                 Properties tableProps,
                                 FarragoTypeFactory typeFactory,
                                 RelDataType rowType,
                                 Map<String,Properties> columnPropMap)
                                 throws SQLException

Creates an instance of a FarragoMedColumnSet corresponding to row data identified by properties rather than container name. This supports the SQL/MED CREATE FOREIGN TABLE statement. As much validation as possible should be performed, including accessing representative data.

Parameters:

localName - the qualified name to assign to the column set within Farrago; this should NOT be used for finding the actual data, since it can be set arbitrarily by the caller; instead, it should be used to implement the RelOptTable.getQualifiedName() method, and can be useful for correlation during debugging

tableProps - properties to use for data location and access

typeFactory - FarragoTypeFactory to use for defining types

rowType - type to impose on the rows of this column set (including column names and types), or null to infer row type; if this is non-null, it must be saved for use by the getRowType() returned from FarragoMedColumnSet

columnPropMap - map from column name to column-specific Properties; this is optional and may only be specified when rowType is also specified (the field names in rowType are used as the keys for columnPropMap)

Returns:

new FarragoMedColumnSet

Throws:

SQLException - if data access is unsuccessful

getRuntimeSupport

Object getRuntimeSupport(Object param)
                         throws SQLException

Gets an object needed for runtime support. Typically, this will be called from code generated by this server. The meaning of this is entirely dependent on the server implementation. If the returned object implements FarragoAllocation, its closeAllocation() method will be called automatically as soon as it is no longer needed.

Parameters:

param - parameter supplied at runtime

Returns:

support object

Throws:

SQLException

registerRules

void registerRules(RelOptPlanner planner)

Gives this wrapper a chance to register any special optimization rules. This method may be called more than once, each time with a different planner instance.

Parameters:

planner - the planner in which the rules should be registered

registerRelMetadataProviders

void registerRelMetadataProviders(ChainedRelMetadataProvider chain)

Gives this wrapper a chance to register one or more RelMetadataProviders in the chain which will be used to answer relational expression metadata queries during optimization. Wrappers which define their own relational expressions will generally need to supply corresponding metadata providers.

Parameters:

chain - receives wrappers's custom providers, if any

releaseResources

void releaseResources()

Gives this wrapper a chance to release any resources.