Standard English uses "may", "can", and "might" in different ways:
may - permission, "You may borrow my rake."
can - ability, "I can lift that log."
might - possibility, "It might rain today."
Unfortunately, in conversational English, their use is often mixed, as
in, "You may use this variable to do X", when in fact, "can" is a better
choice. Similarly, "It may crash" is better stated, "It might crash".
Also update two error messages mentioned in the documenation to match.
can create or modify rules for the table. Do setRuleCheckAsUser() while
loading rules into the relcache, rather than when defining a rule. This
ensures that permission checks for tables referenced in a rule are done with
respect to the current owner of the rule's table, whereas formerly ALTER TABLE
OWNER would fail to update the permission checking for associated rules.
Removal of separate RULE privilege is needed to prevent various scenarios
in which a grantee of RULE privilege could effectively have any privilege
of the table owner. For backwards compatibility, GRANT/REVOKE RULE is still
accepted, but it doesn't do anything. Per discussion here:
http://archives.postgresql.org/pgsql-hackers/2006-04/msg01138.php
Assign the fixed user id 1 to the user created by initdb.
A stand-alone backend will always set the user id to 1.
(Consequently, the name of that user is no longer important.)
In stand-alone mode, the user id 1 will have implicit superuser
status, to allow repairs even if there are no users defined.
Print a warning message when starting in stand-alone mode when no
users are defined.
Disallow dropping the current user and session user.
Granting/revoking superuser status also grants/revokes usecatupd.
(Previously, it would never grant it back. This could lead to "deadlocks".)
CREATE USER and CREATE GROUP will start allocating user ids at 100
(unless explicitly specified), to prevent accidental creation of a
superuser (plus some room for future extensions).
adjustments. Note that many tables are being abused with *really* long
description columns. Should probably shrink those columns to be more
concise, and move some of the info to follow-on reference notes.
reference page to new configuration system. Big update to administrator's
guide, chapters Runtime environment, Client authentication, and User
management, the latter two were part of the old Security chapter.