Unconditional log groups log the before images of specified columns when the table is changed, regardless of whether the change affected any of the specified columns. Unconditional log groups are sometimes referred to as "always log groups." Conditional log groups log the before images of all specified columns only if at least one of the columns in the log group is changed.
is the entire column of table stored/ only the respective row?? - post by ravi_eze
Oracle recommends that you use a nonzero wait time for the first dequeue call on a queue in a session, and then use a zero wait time with the NEXT_MESSAGE navigation option for subsequent dequeue calls.
Posted from Diigo. The rest of my favorite links are here.