Re: Slow statement when using JDBC - Mailing list pgsql-jdbc

I apologize I didn't paste the original query.  The original query is more complex in fact.  Please, let me explain further:

select
DISTINCT
EVENT.ID, ORIGIN.ID AS ORIGINID,EVENT.PREFERRED_ORIGIN_ID AS PREFERRED_ORIGIN,
    EVENT.CONTRIBUTOR, ORIGIN.TIME, ORIGIN.LATITUDE, ORIGIN.LONGITUDE, ORIGIN.DEPTH,ORIGIN.EVTYPE, "
    ORIGIN.CATALOG, ORIGIN.AUTHOR OAUTHOR, ORIGIN.CONTRIBUTOR OCONTRIBUTOR,MAGNITUDE.ID AS MAGID,"
    MAGNITUDE.MAGNITUDE,MAGNITUDE.TYPE AS MAGTYPE "
   
from event.event join event.origin on event.id=origin.eventid
        left join event.magnitude on origin.id=event.magnitude.origin_id "
WHERE EXISTS(select origin_id from event.magnitude where  magnitude.magnitude>=?
 
and my code is:

PreparedStatement stmt = psqlConnection.prepareStatement(sql, ResultSet.TYPE_FORWARD_ONLY, ResultSet.CONCUR_READ_ONLY);
org.postgresql.PGStatement pgstmt = (org.postgresql.PGStatement)stmt;
 pgstmt.setPrepareThreshold(1);

boolean usingServerPrepare = pgstmt.isUseServerPrepare();
System.out.println("Execution: , Used server side: " + usingServerPrepare );
           
           
stmt.setDouble(1, new Double(7.5));
stmt.setFetchSize(200);
long old = System.currentTimeMillis();
ResultSet rs = stmt.executeQuery();
System.out.println("Execution time: "+(System.currentTimeMillis()-old)+" ms.");


In fact the code is coming from the postgres manual to keep it very simple.  Now the interesting part is that after your email, I ran a
SELECT * FROM X WHERE X.ID>7

and it ran in 7 ms, but when did

SELECT * FROM X WHERE X.ID>?

It ran in 319 ms.  While binding variables is slowing the query 10 times, the time difference is not comparable to when I run my original query.  200 ms to 31000 ms.  So my question is about execution plans.  is the execution plan is different when binding variables?  I read as much as I can find from the Postgres manual, but can't find something to hint about what I am doing wrong. 

By the way, I changed the value with for prepareThreshold but id didn't make any difference.  But the conclusion is binding variables based on the code I run is always slower.

Thank you