parse analysis and into the execution code (in tablecmds.c). This
eliminates a lot of unreasonably complex code that needed to have two
or more execution paths in case it was dealing with a not-yet-created
table column vs. an already-existing one. The execution code is always
dealing with already-created tables and so needs only one case. This
also eliminates some potential race conditions (the table wasn't locked
between parse analysis and execution), makes it easy to fix the gripe
about wrong referenced-column names generating a misleading error message,
and lets us easily add a dependency from the foreign-key constraint to
the unique index that it requires the referenced table to have. (Cf.
complaint from Kris Jurka 12-Sep-2002 on pgsql-bugs.)
Also, third try at building a deletion mechanism that is not sensitive
to the order in which pg_depend entries are visited. Adding the above-
mentioned dependency exposed the folly of what dependency.c had been
doing: it failed for cases where B depends on C while both auto-depend
on A. Dropping A should succeed in this case, but was failing if C
happened to be visited before B. It appears the only solution is two
separate walks over the dependency tree.
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.
PostgreSQL Daemon
Bruce Momjian
Tom Lane