RE: Journal records written to disk

This might be not quite true - simply turning on commitment control on a 
journaled PF results in some caching of the journal entries. See the entry at

http://archive.midrange.com/midrange-l/200305/msg00024.html

for more information and a great link to articles by Rick Turner, formerly of 
IBM.

Vern
-------------- Original message -------------- 
From: "Christen, Duane J." <dchristen@xxxxxxxxxxxxx> 

Actually commitment control has very little to do with journal entries being 
written, the major difference is that when under commitment control a 
journal entry for a table will contain the transaction id for that 
commitment cycle'. 

If a file is journaled, any journal entries created by the DBMS are written 
to disk "instantly" (sequentially). If a failure occurs you may loose the DB 
records that are in mainstore but during the IPL the system will use the 
journals to rebuild the missing DB changes to the table(s). 
If you are under commitment control and a rollback is issued, explicitly or 
implicitly (job ended) the journal entries for that transaction are used to 
remove the transaction from the table(s) that were part of that transaction. 
The same occurs on an IPL after a system failure, the journal entries are 
used to remove the transaction from the table(s). 

Duane Christen