Database schemas: search_path

Hi all,

I've organized my database design in multiple schemas, and migrated my existing tables to different schemas by using a simple how-to I found in this list history.
But what I couldn't find was a way to make this schemata fully transparent to my application - which does selects directly to tables instead to schema.table. I know that I can always set the search_path environmnet variable, but I have to do it on each session. I'd like to know if there is a way to make my set search_path persistent on the database, no matter the session.
I believe that this is supported, but couldn't find out how to make it. Can someone help me?

Having to add the 'set search_path = xxx,yyyy,zzzzz' everytime I connect is pain for me and my application.

Another question I have is:
Let's say I have a simple database with 100 tables, divided in 10 schemas with 10 tables in each. Let's say that my last schema is 10th_schema and my last table is z_table (last by creation - is the most recent created table, so I assume it's the last table on the database). My search_path is ascending from the 1st_schema to the 10th_schema.
Would my querie times/performance on table z_table be faster if this table was created on the 1st_schema ?
How does postgres make this search on the search_path to find where a table is in?

Thanks for your help, cya!

Regards,
Igor
--
igor(at)providerst(dot)com(dot)br