have adequate mechanisms for tracking the contents of databases and
tablespaces). This solves the longstanding problem that you can drop a
user who still owns objects and/or has access permissions.
Alvaro Herrera, with some kibitzing from Tom Lane.
Also performed an initial run through of upgrading our Copyright date to
extend to 2005 ... first run here was very simple ... change everything
where: grep 1996-2004 && the word 'Copyright' ... scanned through the
generated list with 'less' first, and after, to make sure that I only
picked up the right entries ...
* ALTER ... ADD COLUMN with defaults and NOT NULL constraints works per SQL
spec. A default is implemented by rewriting the table with the new value
stored in each row.
* ALTER COLUMN TYPE. You can change a column's datatype to anything you
want, so long as you can specify how to convert the old value. Rewrites
the table. (Possible future improvement: optimize no-op conversions such
as varchar(N) to varchar(N+1).)
* Multiple ALTER actions in a single ALTER TABLE command. You can perform
any number of column additions, type changes, and constraint additions with
only one pass over the table contents.
Basic documentation provided in ALTER TABLE ref page, but some more docs
work is needed.
Original patch from Rod Taylor, additional work from Tom Lane.
of an index can now be a computed expression instead of a simple variable.
Restrictions on expressions are the same as for predicates (only immutable
functions, no sub-selects). This fixes problems recently introduced with
inlining SQL functions, because the inlining transformation is applied to
both expression trees so the planner can still match them up. Along the
way, improve efficiency of handling index predicates (both predicates and
index expressions are now cached by the relcache) and fix 7.3 oversight
that didn't record dependencies of predicate expressions.
cleaning out temp namespaces. We don't really want the server log to be
cluttered with 'Drop cascades to table foo' every time someone uses a
temp table...
Instead of grovelling through pg_class to find them, make use of the
handy dandy dependency mechanism: just delete everything that depends
on our temp schema. Unlike the pg_class scan, the dependency mechanism
is smart enough to delete things in an order that doesn't fall foul of
any dependency restrictions. Fixes problem reported by David Heggie:
a temp table with a serial column may cause a backend FATAL exit at
shutdown time, if it chances to try to delete the temp sequence first.
to build dependencies for rules, constraint expressions, and default
expressions. Repair some problems in the original design of
recursiveDeletion() exposed by more complex dependency sets. Fix
regression tests that were deleting things in illegal sequences.
pg_relcheck is gone; CHECK, UNIQUE, PRIMARY KEY, and FOREIGN KEY
constraints all have real live entries in pg_constraint. pg_depend
exists, and RESTRICT/CASCADE options work on most kinds of DROP;
however, pg_depend is not yet very well populated with dependencies.
(Most of the ones that are present at this point just replace formerly
hardwired associations, such as the implicit drop of a relation's pg_type
entry when the relation is dropped.) Need to add more logic to create
dependency entries, improve pg_dump to dump constraints in place of
indexes and triggers, and add some regression tests.
Tom Lane
PostgreSQL Daemon
Bruce Momjian