wood burning stoves 2.0*
The moose likes Developer Certification (SCJD/OCMJD) and the fly likes Q on Concurrent Accessing Big Moose Saloon
  Search | Java FAQ | Recent Topics | Flagged Topics | Hot Topics | Zero Replies
Register / Login


Win a copy of Android Security Essentials Live Lessons this week in the Android forum!
JavaRanch » Java Forums » Certification » Developer Certification (SCJD/OCMJD)
Bookmark "Q on Concurrent Accessing" Watch "Q on Concurrent Accessing" New topic
Author

Q on Concurrent Accessing

Walter Tang
Greenhorn

Joined: Aug 13, 2004
Posts: 25
Hi all,

Can I assume that only one program can access the database file at a time. In that case, we only need to handle the concurrent accessing on server side but not database file, which is much easier. But I dont really like this way to program, 'cause it is way less efficient than the way to asscess database file by mutilple threads (clients). What do you think?
[ August 27, 2004: Message edited by: Walter Tang ]

SCJP
Nathaniel Stoddard
Ranch Hand

Joined: May 29, 2003
Posts: 1258
You should read your requirements carefully. I did the URLyBird project a very long time ago and it specifically said that we could assume only one program was accessing the database file at a time.


Nathaniel Stodard<br />SCJP, SCJD, SCWCD, SCBCD, SCDJWS, ICAD, ICSD, ICED
Walter Tang
Greenhorn

Joined: Aug 13, 2004
Posts: 25
Originally posted by Nathaniel Stoddard:
You should read your requirements carefully. I did the URLyBird project a very long time ago and it specifically said that we could assume only one program was accessing the database file at a time.


Hi Nathaniel, Thanks for your reply.

Yeah I read that too. But I am just alittle confused. In the database interface, it asked me to implement the lock and unlock record. I am just wondering if we handle the concurrent accessing of multiple clients at server level, why should we implement the lock and unlock on database record since only one client program will acess the file.
Walter Tang
Greenhorn

Joined: Aug 13, 2004
Posts: 25
Originally posted by Nathaniel Stoddard:
You should read your requirements carefully. I did the URLyBird project a very long time ago and it specifically said that we could assume only one program was accessing the database file at a time.


Hello again,

I just solved my question by searching an old postpost
Omar Kalaldeh
Ranch Hand

Joined: Jun 08, 2004
Posts: 58
Hi Walter,

They said you can assume one program can access the database, and that dose not mean one thread only can access the database, those tow things are completely different.

When they say one program can access the data file that mean there is only one server accessing the database, and there is no other program accessing that data file in the same time, for example you can assume there is no editor program accessing that file or there is no other server accessing that file.

But still in your server program it will handle concurrent client�s (multi threads).


Best Regards <br /> <br />Omar F. Kalaldah<br />---------------------<br />SCJP, SCJD, SCBCD
Walter Tang
Greenhorn

Joined: Aug 13, 2004
Posts: 25
Originally posted by Omar Kalaldeh:
Hi Walter,

They said you can assume one program can access the database, and that dose not mean one thread only can access the database, those tow things are completely different.

When they say one program can access the data file that mean there is only one server accessing the database, and there is no other program accessing that data file in the same time, for example you can assume there is no editor program accessing that file or there is no other server accessing that file.

But still in your server program it will handle concurrent client�s (multi threads).


Hi Omar, I see the difference. Thank you very much for your help
 
Don't get me started about those stupid light bulbs.
 
subject: Q on Concurrent Accessing
 
Similar Threads
exclusive lock() yes or not?
Local mode == one client?
B&S: Locking
Requirement
Local mode an d remote mode