gov.lbl.dsd.p2pio
Class P2PQuery

java.lang.Object
  gov.lbl.dsd.p2pio.MsgElement
      gov.lbl.dsd.p2pio.Query
          gov.lbl.dsd.p2pio.P2PQuery

public class P2PQuery

extends Query

A Peer to Peer query contains three parts, a dataSourceQuery, a mergeOperator and a streamQuery.

1. dataSourceQuery: a query executed against each individual data source in the P2P network, producing an ItemSet.
2. mergeOperator: an operator that tells if the item sets from multiple nodes should be merged via set UNION or list CONCAT.
3. streamQuery: a query executed against the item set produced by step 2. If the optional streamQuery is null (i.e. missing), the input stream remains unaffected.

Version:

$Revision: 1.3 $, $Date: 2004/01/30 01:18:03 $

Field Summary

static String	CONCAT
static String	UNION Legal values for mergeOperator are UNION and CONCAT

Constructor Summary

P2PQuery(Query dataSourceQuery, String mergeOperator, Query streamQuery, String cgiCommand)

Method Summary

String	getCgiCommand()
Query	getDataSourceQuery()
String	getMergeOperator()
Query	getStreamQuery()

Methods inherited from class gov.lbl.dsd.p2pio.MsgElement

toDOM, toString, toXOM

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

UNION

public static final String UNION

Legal values for mergeOperator are UNION and CONCAT

See Also:

Constant Field Values

CONCAT

public static final String CONCAT

See Also:

Constant Field Values

Constructor Detail

P2PQuery

public P2PQuery(Query dataSourceQuery,
                String mergeOperator,
                Query streamQuery,
                String cgiCommand)

Method Detail

getDataSourceQuery

public Query getDataSourceQuery()

getStreamQuery

public Query getStreamQuery()

getMergeOperator

public String getMergeOperator()

getCgiCommand

public String getCgiCommand()