Re: how synchronous is Oracle?

"Robert A.M. van Lopik" <lopik_at_mail.telepac.pt> wrote in message news:<3e66fee5$0$10173$a729d347_at_news.telepac.pt>...
> The question is: does Oracle guarantee that committed inserts are
> "immediately" visible to other users, or is there a possibility, e.g. on a
> heavily loaded system, that proces B will not retrieve the record, although
> it will see it at a somewhat later time?

Robert,
you were asking for a simple answer: Yes, Oracle does guarantee that. It uses locking and marking (dirty blocks) mechanisms to ensure that. If in your scenario process A puts a lot of data to be committed into the database, then the affected rows or even the table itself gets locked until the commit has been completed. Process B has to wait for write completion if the server is unable to retrieve the desired data blocks from the cache.

Hope this helped,
Uwe Received on Thu Mar 06 2003 - 11:09:41 CST