apunhiran said:
Hi,
Thanks a lot for the explanation, that almost completes my understanding of the PROGRESS database architecture.
Small clarifications just to know if I have understood things right.
1. Structure file - database definition file - init.ora in oracle
2. .lg file - tracks database events and errors - alert_DBNAME.log in oracle
3. Database control area - data dictionary of the database - data dictionary in oracle(system tablespace).
4.Transaction log area - used for distributed computing to validate commits of a transaction on various databases.
Please let me know if I have understood things right.
Secondly how does commit and rollback occurs in PROGRESS, why we get errors like .Bi full and database stalls.
Thanks
Regards
Apun Hiran
Pretty close Apun,
1. Structure file - database definition file - init.ora in oracle
*** The .st structure is is actully for db creation and as a backup of the actual physical layout which is stored in the .db file.
2. .lg file - tracks database events and errors - alert_DBNAME.log in oracle
*** Yes
3. Database control area - data dictionary of the database - data dictionary in oracle(system tablespace).
*** schema
4.Transaction log area - used for distributed computing to validate commits of a transaction on various databases.
*** Yes, this is an option area and is only used when transactions span multiple databases.
Secondly how does commit and rollback occurs in PROGRESS
*** Durring any transaction or subtransaction, if a error condition rises (a system or software error, a user pressing the stop or undo key, or programatically defined end, undo situation, any active transactions stored as notes in the .bi are rolled back on a per user basis.
why we get errors like .Bi full and database stalls.
.bi full, if you have a fixed length bi and it fills up.
bistall (if this is what you are talking about), the -bistall allows the administrator to specify a point below the bi size where the database will stall and allow for the addition of additionall bi extents so processing can resume. There is a section in the administration guide on sizing the bi.
If you meant why would your application seem to stall or stop functioning for a short time, you need to look at things like -bigrow and database extent sizing. (The system is enlarging object in need).
Other stalling could be caused by a number of things, normally faulty programming or hardware issues.
All in all, I think you'll find Progress much easier to deal with than Oracle, as long as you don't let your Oracle experiance mess with your mind.
