<div>Excuse me,</div><div><br></div><div>I'm new for pgpool-II.</div><div>Here comes a trouble for me,about the diffenences between jdbc query and psql direct executing in parallel mode.</div><div>I built my cluster in parallel mode,following the tutorial </div>
<div>(<a href="http://pgpool.projects.postgresql.org/pgpool-II/doc/tutorial-ja.html#parallel" target="_blank">http://pgpool.projects.postgresql.org/pgpool-II/doc/tutorial-ja.html#parallel</a>) completely.</div><div><br></div>
<div>My 4 hosts showing as below：</div>
<div><br></div><div>pgpool-adm(pgpool-II installed ,working port 9999)</div><div>backend-0(datanode 1 on port 5432)</div><div>backend-1(datanode 2 on port 5432)</div><div>backend-2(datanode 3 on port 5432).</div><div><br>
</div><div>For a distributed table,</div><div>I can get the merged result set through the command lines in the host "pgpool-adm" with "psql" command:</div><div><br></div><div>[root@pgpool-adm ~]# psql -p 9999 -c "select BID,COUNT(*),MIN(aid),MAX(AID) from pgbench_accounts GROUP BY BID" bench_parallel -U postgres</div>
<div> bid | count | min | max </div><div>-----+--------+--------+--------</div><div> 1 | 100000 | 1 | 100000</div><div> 3 | 100000 | 200001 | 300000</div><div> 2 | 100000 | 100001 | 200000</div><div>(3 rows)</div>
<div><br></div><div><br></div><div>But in JDBC side(via DBVisualizer or Java programming),</div><div>I can only get the result set from one node,just like psql on one of the backend nodes:</div><div><br></div><div>[root@pgpool-adm ~]# psql -h backend-2 -c "select BID,COUNT(*),MIN(aid),MAX(AID) from pgbench_accounts GROUP BY BID" bench_parallel -U postgres</div>
<div> bid | count | min | max </div><div>-----+--------+--------+--------</div><div> 2 | 100000 | 100001 | 200000</div><div>(1 row)</div><div><br></div><div>It seems that the JDBC would random choose one among the 3 backend datanodes when building the db-connection,so I can only</div>
<div>make query on just one node. </div><div><br></div><div><br></div><div>In fact,JDBC is what I need...so can anyone help?</div><div>anyone can catact me both in english or japanese.</div><div><br></div><div>By the way,the pgAdmin tool can't make connection to host "pgpool-adm" on 9999,just tells that "An error has occurred"⋯⋯</div>
<div><br></div><div>That's all.</div><div><br></div><div><br></div><div>Thanks at first and best regards~</div><div><br></div><div>Herro</div>