referencing table does not change the tuple's FK column(s), we don't bother
to check the PK table since the constraint was presumably already valid.
However, the check is still necessary if the tuple was inserted by our own
transaction, since in that case the INSERT trigger will conclude it need not
make the check (since its version of the tuple has been deleted). We got this
right for simple cases, but not when the insert and update are in different
subtransactions of the current top-level transaction; in such cases the FK
check would never be made at all. (Hence, problem dates back to 8.0 when
subtransactions were added --- it's actually the subtransaction version of a
bug fixed in 7.3.5.) Fix, and add regression test cases. Report and fix by
Affan Salman.
* 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.
incompatible enough to prevent indexscanning the referenced table. Also,
improve the error message that pops out when we can't implement the FK at
all for lack of a usable equality operator. Fabien Coelho, with some review
by Tom Lane.
large objects. Dump all these in pg_dump; also add code to pg_dump
user-defined conversions. Make psql's large object code rely on
the backend for inserting/deleting LOB comments, instead of trying to
hack pg_description directly. Documentation and regression tests added.
Christopher Kings-Lynne, code reviewed by Tom
rule split the query into one INSERT and one UPDATE where the UPDATE
then hit's the just created row without modifying the key fields again.
In this special case, the new key slipped in totally unchecked.
Jan
that the regression tests for foreign keys didn't seem to test
a deferred constraint that was not satisified by a later
statement and was not made immediate by set constraints,
so here's a simple added test with a single invalid insert and
a commit.
Stephan Szabo
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.
handled as special productions. This is needed to keep us honest about
user-schema type names that happen to coincide with system type names.
Per pghackers discussion 24-Apr. To avoid bloating the keyword list
too much, I removed the translations for datetime, timespan, and lztext,
all of which were slated for destruction several versions back anyway.
entries, per pghackers discussion. This fixes aggregates to live in
namespaces, and also simplifies/speeds up lookup in parse_func.c.
Also, add a 'proimplicit' flag to pg_proc that controls whether a type
coercion function may be invoked implicitly, or only explicitly. The
current settings of these flags are more permissive than I would like,
but we will need to debate and refine the behavior; for now, I avoided
breaking regression tests as much as I could.
in referencing and referenced columns of an fk constraint
aren't comparable using '=' at constraint definition time
rather than insert/update time.
Stephan Szabo
I believe this should fix the issue that Philip Warner
noticed about the check for unique constraints meeting the
referenced keys of a foreign key constraint allowing the
specification of a subset of a foreign key instead of
rejecting it. I also added tests for a base case of
this to the foreign key and alter table tests and patches
for expected output.
didn't hear anything about, but which would
have broken with the function manager changes
anyway.
Well, this patch checks that a unique constraint
of some form (unique or pk) is on the referenced
columns of an FK constraint and that the columns
in the referencing table exist at creation time.
The former is to move closer to SQL compatibility
and the latter is in answer to a bug report.
I also added a basic check of this functionality
to the alter table and foreign key regression
tests.
Stephan Szabo
sszabo@bigpanda.com
