How do you implement 'Dirty Read/ Write' concept?

Question

Hi,
I need to implement dirty read/ write concept into my procedure. I wanted to know how to go about it. Does Oracle have provide a way to do this or is this something to be worked out with some logic manually?
Can someone suggest the exact logic I should follow or chalk out a simple algorithm.
Any kind of information on this would be much appreciated.
Thanks,
Amrita.

Answer 1

Sorry for this late reply.<br>
My first reply should have contained an example on how to implement it for the kicks. Don't use this code for anything else but a test. It's absolutely worthless application-wise. But it proves that some dirty read/write functionality can be obtained if one twists everything that is good. Here goes. First I create two java classes and two PL/SQL "wrappers". Then - simply connect with session 1 and invoke exec dirty_write<br>
make no commit ... and let session 2 select dirty_read from dual. You'll notice that the data written by session 1 is read by session 2.<br>
create or replace and compile
java source named "FileAppendTest"
as
import java.io.File;
import java.io.FileOutputStream;
public class FileAppendTest {
static public void append() {
  try {
    int vSomethingToWrite = 9;
   File vFile = new File("c:\\db_out.txt");
   FileOutputStream vAppendFile = new FileOutputStream(vFile, true);
   vAppendFile.write ( vSomethingToWrite );
  vAppendFile.close();
  } catch (Exception e) {
   // let this test hide all errors
create or replace and compile
java source named "DirtyReadTest"
as
import java.io.File;
import java.io.FileInputStream;
import java.io.File;
import java.io.FileInputStream;
public class DirtyReadTest {
static public int read() {
  int vError = 0;
  try {
   File vFile = new File("c:\\db_out.txt");
   FileInputStream vReadFile = new FileInputStream(vFile);
   return vReadFile.read();
  } catch (Exception e) {
   return vError;
create or replace procedure dirty_write as
language java
name 'FileAppendTest.append()';
create or replace function dirty_read return number as
language java
name 'DirtyReadTest.read() return integer';
-- as I mentioned earlier. Only try this code for the fun of it. Don't consider it for anything remotely usable in an application.