CS297-298 Project News Feed

Feature Description:
 With this feature, user no longer have to go into output file and 
check the result for ARIES or NATIX.  For example, user can add expected result into a flat file 
name in the following directory:

verifyFile = c://an//cs297//xmldb//unit//verify//file-name.txt

Solution:
 Wrote ThVerifyResult which contains a loop through the lines in the verify file and look for it in output file.
   

Feature Description: 
 Add a new property in dbsystem.properties to direct 
output from the program to a file or to standard IO.

Solution:
 Done
   

Bug Description:
 When a page is written to disk, it's a block of bytes which is 
hard to see sometime.

Solution:
 The page still write to disk as it used to be. 

However, for debug purposes, add code to format the page so user can look into its content.

This new page format is named as page-number.pageformatted
   

Bug Description: 
 CLR is written for rollback operation only, not during restart recovery.

Solution:
  Fixed
   

Feature Description: Implement sort for ArrayList of log record.

Solution:
public class ThLogRecord implements Comparable
{
.....
public int compareTo(Object obj) 
  {
     ThLogRecord log = (ThLogRecord) obj;
     int result = lsN.compareTo(log.getLSN());
     if (result < 0)
        return 1;
     else if (result > 0)
        return -1;
     return result;       
  }  
}

How to call:
java.util.Collections.sort(redologs); 

Problem Description:
 Add CLR feature.
   

Bug Description:
 During scanning log records phase,
instead of create an instance of every log record and then check to 
see if the log lsn is match with the current lsn, check the lsn of the comming log record. 
If it match with the current, create the log record. If not, skip it.

Fix Description:
 Check for a matched LSN of the interest before create an instance of a log record.

   

Problem Description:
  NullPointerException throws during Restart Recovery for Update and Delete Operations.
  It was because forgot to pass path value when write out log 
records but expect a value when read in.

Fix Description:
  Provide the fix in reateLogRecord function in LogManager.
   

Problem Description:
  Suppose T1 update and commited
  T2 also update and commited and with additional updates.
  => Get un-expect values

Fix Description:
  sort log records before calling redos in redo phase.
     

Problem Description:
 For the case where one transaction updated the document and the second transaction goes in 
and modif on top of it, how should we handle this?

Problem fix:
 For simplicity because of time related and our concentration was on Recovery Manager, we decided ignore locking implementaion. 
Thus, we assume transactions are serializable. 
 We assume UR-committed read (UR)
 We assume that we can't rollback operations that are not nest by other operations.

For example:
 T1 load data into a document.
 T2 insert some data

Up to this point, we can only rollback T2 inserts because:
 T2 updates 
   

Bug Description:
 This bug affect only when the NATIX switch is on.
 Because PageInterpreter has it's own log records and it won't publish to Log Manager until the 
Page is flushed to disk by Buffer Manager's swapping, it still keep 
the log locally in PageInterpreter.
Thus, during rollbak, Log Manger can't read the log.

Bug Fix:
 Make sure log records are flushed so Log Manager can process it.
   

Problem Description:
  Rollback Operation rollback less than it suppose to



   

Done
   

Can't get Space Map Page to work. It often throws exception if split often.

Solution: Not at the moment.
=> Back out the code for this

   

Bug Description:
 Rollback operation such as LOAD often produce pages contain no longer in use pages.

Fix Description:
 Call buffer manager to free these pages.
   

1. Bug Description:
 This is actually a new feature.

2. Bug Fix:
 XML structure written to page on disk is named as Space Map Page. 
 Handle overflow: split when this page is overflow by moving 1/2 of struct nodes in the page to the new node.
   

1. Bug Description: 
 Structure printed out null values when there is a page swap in Buffer Manager.

 This is because of the mis calculate in offset of nodes during toHex() function. 
   
2. Fix Description:
 re-calculate offset for page.toHex() function.

1. Bug Description: 
 Duplicate call to LOAD operation at parser, cause duplicate call to open data input file and LOAD into xml document.

2. Fix Description:
 In ThParser, reset a local variable before the next iteration.

   

Everything breaks right now as the result of changed in page structure
   

Add code to write XML tree structure to disk.

Status: working.
   

Change the way a page is written to disk as file of HEX instead of object.
   

Re-organize program so that we can select recovery methode:

* Create interface IThPage 
* ThPage and ThPageInterpreter implements IThPage.
* ThPageInterpreter extends ThPage.

Status: working. 
   

* Complete Update and Rollback for UPDATE operation
   

* Complete Rollback for DELETE operations.
* Complete test of load, inserts, delete, and rollbacks with transaction interleave.

   

Rollback for Load operation is also working.

Debugging on Rollback for Delete Operation.

 Issue: Should we delete the data and do log apply to rollback or just set a deleted bit and do nothing so that during rollback, we only flip back this bit
 
   

+ Add Recovery Manager Class to handle rollback. 

+ Working for the case:
Insert ....
Rollback;

+ Target features:
  More complicated rollback operations.

  More transactions
  
+ Difficulties: handle nesting transactions

+ Target date: 10/05/04

Add more information used by Recovery Manager

Improve human readability log record for debugging purpose - Change writeUTF() to writebytes().
   

+ Add more delete operation 
+ Change page size
+ Add more bit that will be used by Recovery manager

Target date: 09/22/04
Done 

Create and make use of Properties file.

Target date: 09/14/04
   

Write log records for create, update, insert, and delete operation. 

Target date: 09/22/04
   

Should be able to support nesting Transaction.

Target date: 09/22/04