[java] database question

First off, 30,000 records is small. Well, unless your average record is 10k or something huge like that.

Second, if you want the full flexibility of a database, JDBC actually is quite easy.. And if you use it with something like Hypersonic SQL DB, you don''t even need to worry about setting up and securing an external database.

If you don''t need everything a database offers, check to see if some combination of the collections libraries (Lists, Sets, Maps, etc) help.

As far as IO speed... Using a decent IO system, 30,000 records shouldn''t take very long to read or write. As long as you don''t read or write the full structure on every change, there shouldn''t be a problem.

If you post the code you''re using, as well as the operations you need to be able to perform, I can probably help quite a bit more.

huh?? 30,000 records is small?? really??
i want to use JDBC, but i read the tutorial and i got confuse...
it said i must install JDBC, driver, and DBMS.
i have bad experience using database!
(can''t use database i made on another computer, must install drivers, very inconvenient!)
and i try to run the JDBC sample, but it use internet connection! i only want to use my database

on local computer, and the source code is very very lack of information.
i usually learn by example, reading all the article makes me sick.

the really problem of using decent IO System is not at the speed actually.
the problem is the memory it takes. i load 50,000 records and got OutofMemory Error!
cos i put all loaded String into a Hashtable (takes 80megs memory after that error)

if using database like paradox or umm oracle maybe... i don''t have to load all the object into memory isn''t it?
adding,removing,and finding records using database SQL is more simple than using Hashtable method i presume. (and doesn''t use extraordinary memory for sure)

so is there class that can make an ArrayList from a file? (without using large memory).
or can u point me to the basic of using JDBC (just for saving, loading, adding, removing, and finding records)
what i want to do is loading all object from a file then put it into a Vector.

okay this is the loader class i use (LoadTest.java) :

import java.io.*;
import java.util.*;

public class LoadTest {
	private static Hashtable dbase = new Hashtable();

	public static void main(String[] args) {
		// load SampleFile.in
		load(new File("SampleFile.in"));
	}

	private static void load(File inputFile) {
	try {
		FileReader in = new FileReader(inputFile);
		BufferedReader readIn = new BufferedReader(in);
		// the first line is the total line in that file
		int dataLength = Integer.parseInt(readIn.readLine());
		int i=0;
		while (i < dataLength) {
			// name of the object
			String header = readIn.readLine();
			i++; // must increment the line everytime we use readIn.readLine()
			// read object''s content
			String content = readIn.readLine(); i++;
			StringBuffer attribute = new StringBuffer();
			boolean finish = false;
			while (!finish) {
				content = readIn.readLine(); i++;
				if (content.equals("===================="))
					finish = true; else
					attribute.append(content).append("\n");
			}
			dbase.put(header, attribute.toString());
		}
		readIn.close();

		// testing database
		Enumeration e = dbase.keys();	// dbase header
		Enumeration attrib = dbase.elements();
		while (e.hasMoreElements()) {
			System.out.println(e.nextElement());
			System.out.println(attrib.nextElement());
		}
		System.out.println("total line = "+i);
	} catch (IOException e) { e.printStackTrace(); }
	}
} 

and input file (SampleFile.in) :

21
Jack
----------
AC = 14
STR = 10
AGL = 8
INT = 4
====================
Marry
----------
AC = 8
STR = 7
AGL = 12
INT = 8
====================
Ken
----------
AC = 20
STR = 25
AGL = 20
INT = 16
====================
 

thank you very much....