Hi Eric and Alexandre
Actually I have got the same question. In my opinion, �ReadWriteLock� only works for extract data from the database and write the data to the database.
For example, a user did a search, found the record number 1,2,3 and its GUI shows the values of these three records. At this moment these records are not locked (for write) anymore. If another user comes, he could get the lock and change the record (for example the record 2). So the record (record 2) showing for the second user and any future users is different comparing with the first user.
I am not sure is this the case or not.
Thanks in advance!