"No locks" is the default, and generally the best solution.
It means that Access locks the table only during the actual write
operation--a tiny fraction of a second. Use this as the default unless you
have a reason to change it.
"All Records" means that Access locks the entire table, which locks everyone
else out. You may need to do this for specific operations (e.g. update
query), but it is not desirable as a default.
"Edited Record" means that when one user is altering the record, it is
read-only to other users. Unless the "record level locking" box is also
checked, the lock occurs on a page of data (2048 bytes in Access 97), which
may actually be several records if they are small in size.
When you use No Locks, you need to train your data entry operators in how to
handle the confiict dialog. Imagine this sequence:
1. Simon notices a client's address is wrong and decides to update it.
2. On another computer, Joanne notices the same client's phone number is
wrong and decides to update without knowing Simon is updating the address at
the same time.
3. Simon saves the address change: no problem, except Joanne is still
editing with the old address.
4. When Joanne goes to save her change, she receives the conflict dialog.
She now has three choices:
o "Save Record" means her phone number is saved, but Simon's new address
will be overwritten with the old one that Joanne still has.
o "Drop Changes" means Simon's changes stand, and hers are lost.
o "Copy to Clipboard" means her changes are copied to the clipboard, and
Simon's changes are displayed on her screen. After reviewing Simon's
changes, if she wishes to overwrite them with her own, she can do so by
clicking the Record Selector, and choosing Paste.
