Hello,
last_login plugin uses dict interface, which does not support "update",
it only supports get, set, unset and atomic inc. Set is implemented
with
'INSERT INTO foo ... ON DUPLICATE UPDATE'. There is no configuration
setting to change this, as dict cannot know without performing a SELECT
that a value already exists.
Ok, now i understand the dict behaviour.
Some clarification in the last-login wiki page would be nice:
* needed Database rights
* Example of last_login in separate table
In my special case i wanted to use the last_login field inside
the mailbox table of postfixadmin.
From the security point of view i don't want dovecot to be able
to insert records in that table. So the only additional right
should be update on the last_login field.
In the case of the last_login plugin there ist a very high probability
the dict key exists because of the previous successfull login which
uses the same table.
If the key does not exist there is a serious problem :-)
Perhaps there shoud be a feature of different types of dicts:
* normal dict (as implemented)
* immutable dict (read only)
* dict with immutable keys (only value writeable)
Kind regards,
Thomas
