A compare and/or sync. database structure?

Hi!

I wanna ask that which pg_dump command line needed if I want to compare two databases?

I have many DBs, but all of them have two versions a development (local) DB and the online (web) DB.

When I want to realize a new function, I develop it locally, and later I sync. it into online DB.

But it is hard: I easily miss some things... :-(

Because of that I want to write some tool that can compare databases.

In DBISAM world I can do it easily, because DBISAM tables very-very near to Delphi DataSets, and I can compare tables/indexes with Delphi comparations.

In Firebird it was harder, because if must compare tables, and later other objects (generators) too... :-(

In PostgreSQL I have two way to compare DBs.

1.) pg_dumps, and textdiff.

2.) get schema (table struct, indexes, etc) from all, and compare them.

The first version is need user SQLs, the second can create alter/create SQLs automatically...

So please help me with your experience: what is the best solution, what is the possible problem that make mistakes with this plan, and how to realize it easily?

Thanks for your help:

   dd