===========================================================================================
  Main thread aoolotion
===========================================================================================

package main;

import java.util.ArrayList;
import java.util.Map;

import com.mycompany.lib.MyLib;

import runnable_single_thread.GetSECFilingInfoData_Runnable;
import runnable_single_thread.GetTickerWithKeyword_Runnable;
import runnable_single_thread.Temp_Runnable;

public class Multithread_Temp_Main {

	public static void main(String[] args){
		
	    String limit_scope = "";
	    
	 		

	    int group_cnt = 80;
	    
	    for ( int i = 0; i < 100; i++ )
	    {
		    
	    	limit_scope = "limit " + String.valueOf( i * group_cnt ) + ", " + String.valueOf( i * group_cnt + group_cnt );
	   // 	System.out.println(limit_scope);;
	    	
	    	Thread thread = new Thread( new Temp_Runnable( limit_scope ) );
		    thread.start();
		    
		    
	//	   if ( i > 2 ) break;
	    }
	    
	   		    
	    
	}

}
============================================================================================
 child thread 
============================================================================================

package runnable_single_thread;

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.net.URL;
import java.net.URLConnection;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import com.mycompany.lib.MyLib;

import tools.LinearRegression;

public class Temp_Runnable implements Runnable {
	
	
	private String limit_scope = "";
	
	public Temp_Runnable(String limit_scope ) {
	      
		this.limit_scope = limit_scope;
		
		System.out.println(this.limit_scope);
		
	}
	
	public void run() {
		// TODO Auto-generated method stub
		
		 MyLib myLib = new MyLib();	 
		Map def_map = myLib.getDSMap();
		      
		System.out.println("Thread starts ");
		
   		try {
   			  		
   			String driver_classname = (String)def_map.get("jdbcclassnm");
		    
	    	String login_id = (String)def_map.get("dbserverid");
	    	
	    	String server_url_web = (String)def_map.get("dbserverurl");
	    	String login_pw_web = (String)def_map.get("dbserverpw");
        	      		       	
       		
            java.lang.Class.forName( driver_classname );
        
        	java.sql.Connection con_web = java.sql.DriverManager.getConnection( server_url_web, login_id, login_pw_web );	
        	
        	java.sql.PreparedStatement stmt = null;
        	java.sql.PreparedStatement stmt_1 = null;
        	
	    	java.sql.ResultSet rs = null;
	    	java.sql.ResultSet rs_1 = null;
	    	
	    	con_web.setAutoCommit(true);
	    	
	    	String backend_sql_string = "";
	    			    	
    		backend_sql_string = 
	    			"select distinct ticker"			  
					+ "  from class_4.ticker_hist "
					+ this.limit_scope
					;
	    	
    		
	    	
	    	System.out.println(backend_sql_string);
	    	
	    	stmt = con_web.prepareStatement( backend_sql_string );			
	    	rs = stmt.executeQuery();
	    	String str = "";
	    	
	    	
	    	int count = 0;
	    	
	    	while ( rs.next() )
	    	{
	    		count = count + 1;
	    		
	    		
	    	//	if ( count > 2 ) break;
	    		
	    		String ticker   = rs.getString( "ticker" );
	    			
	    		System.out.println( "process ticker: " + ticker );
	    		
	    	}
	        
		
   		}
   		catch ( Exception e )
   		{
   			System.out.println( e.getMessage() );
   			e.printStackTrace();
   		}

	}

}
==================================================================================