Multiple threads calling the same stored proc with different parameters

Question

Hi,
I have a stored procedure which will be called by 8 threads. Every time it takes in a different parameter.
Actual execution time for this proc (irrespective of the parameter) is around 2 seconds. But when I call the 8 threads, I see that the total time taken (END TO END) is around 16 seconds. Threads do acquire a read lock right? Is there a way i can get over this issue?
Please let me know.

Answer 1

Sybase IQ is the database. I am using a thread pool. The time taken to execute this procedure without threads is about 2 seconds. It takes 16 seconds when I start using threads.
I do something like this :
///////////////////////// databaseThreadPool.java
* example of a fixed-size thread pool using the
* executors introduced in Java 5
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
public class databaseThreadPool
public static void main(String[] args)
* create a thread pool with four threads
ExecutorService execSvc = Executors.newFixedThreadPool( 8);
* place six tasks in the work queue for the thread pool
for( int i = 0; i < 6; i++ )
execSvc.execute( new CountDown() );
     long a =System.currentTimeMillis();
execSvc.execute( new databaseThread("00055","YTD","GROSS") );
execSvc.execute( new databaseThread("00055","YTD","NET") );
execSvc.execute( new databaseThread("00055","YTM","GROSS") );
execSvc.execute( new databaseThread("00055","YTM","NET") );
execSvc.execute( new databaseThread("00055","LY","GROSS") );
execSvc.execute( new databaseThread("00055","LY","NET") );
execSvc.execute( new databaseThread("00055","LLY","GROSS") );
execSvc.execute( new databaseThread("00055","LLY","NET") );
     long b =System.currentTimeMillis();
     try{
     while(databaseThread.done!=8)
          Thread.sleep(1000);
     catch(Exception ex){}
execSvc.shutdown();
System.out.println("END TO END TIME TAKEN : "+(b-a));
/////////////////////////////////////////////////////////// databaseThread.java
import java.io.PrintWriter;
import java.sql.CallableStatement;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.Statement;
import java.io.PrintWriter;
import java.sql.CallableStatement;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import java.sql.Statement;
import java.io.IOException;
public class databaseThread implements Runnable
protected int count = 8;
* the following counter is incremented once
* each time the class is instantiated, giving each
* instance a unique number, which is printed in run()
private static int taskCount = 0;
private final int id = taskCount++;
private String gpNum;
private String time;
private String domain;
public static int i=0;
public static int done=0;
PrintWriter out = null;
Connection connection = null;
Statement statement;
ResultSet rs;
ResultSetMetaData rsmd;
     CallableStatement cStmt = null;
public databaseThread(String gpNum, String time, String domain) {
this.gpNum=gpNum;
this.time=time;
this.domain=domain;
* print the id and the iteration count to the console, then
* yield to another thread.
public void run()
     try
     Class.forName("com.sybase.jdbc3.jdbc.SybDriver");
     connection = DriverManager.getConnection("jdbc:sybase:Tds:XXXXXXXXXXX:XXXXXXX", "cp_dbo","cp_dbo");
     statement = connection.createStatement();
          cStmt=connection.prepareCall("{call XXXXXX ?,?,?)}");
          cStmt.setString(1,gpNum);
          cStmt.setString(2, time);
          cStmt.setString(3,domain);
          long a =System.currentTimeMillis();
          rs=cStmt.executeQuery();
          long b=System.currentTimeMillis();
          System.out.println(id+" Time taken by to execute Query : "+(b-a));
     //rsmd=rs.getMetaData();
          while(rs.next())
          Thread.yield();
     catch (ClassNotFoundException e) {
          System.out.println("Driver Error" );
          e.printStackTrace();
          } catch (SQLException e) {
          System.out.println("SQLException: " + e.getMessage());
}