Newbie questions

Hello everyone -

I'm new to PostgreSQL so bear with me if this seems like obvious
questions. (By the way, I did read the FAQ at
http://metalab.unc.edu/LDP/HOWTO/PostgreSQL-HOWTO.html#toc26 but these
questions weren't addressed there...)

Database design - CASE tools
============================
Most database developers use some kind of computer-assisted
software-engineering (CASE) tool during the database design phase. CASE
tools usually provide a visual way of defining tables, columns, primary
keys, foreign keys, indexes, etc. Some example of popular CASE tools are
ER/Studio, ERwin, InfoModeler, Oracle Designer/2000, PowerDesigner,
Silverrun, xCase, Embarcadero and System Architect.

Once the developer has created a data model in the CASE tool (usually an
entity-relationship diagram), the tool outputs an SQL DDL
(data-definition language) script in the chosen "dialect" of SQL
(PostgreSQL, Oracle, DB2, Sybase, MS-SQL, etc) and then the developer
executes this script to create the database. Many CASE tools provide
"two-way trips" meaning that the you can *input* an existing SQL
database schema (either in the form of the DDL script which defines it
or by connecting to the actual database, usually via ODBC, and
inspecting the "meta-data" or schema information) and then *output* a
data-model in the CASE tool format, suitable for further manipulation in
the CASE tool.

What CASE tools are available which output the PostgreSQL "dialect" of
SQL? What has people's experience been with CASE tools and PostgreSQL?
For people who *don't* use a CASE tool: what do you find to be the most
efficient method of defining your database schema?

Additional SQL features
=======================
Several DBMS vendors have included additional features in their
"dialect" of SQL which may or may not be specified by any of the ANSI
standards. Examples include triggers, stored procedures, and declarative
referential integrity, and automatic two-phase commit. (Borland's
Interbase 5.5 is a good example which incorporates all these features.)

Does PostgreSQL provide any of these additional features?

Thanks for the help!

- Scott Alexander
scott(dot)alexander(at)mindspring(dot)com