How many no. of clients can access database simultaneously?

Hi,

Here I have some queries on which I didn't get document. Please help me. Thanks in advance.

1: How many maximum number of clients can access the same database at a time?

2: What is the recovery mechanism provided for PostgreSQL? Is there any provision for comma separated records or file?

3: Are there any interfaces provided in C/C++ to change or set the DATESTYLE and TIMESTAMP?

4: When client accesses the database from other host machine, we provide the ipaddress and hostname for connection. My question is about, priority is
given to which parameter for connecting to the remote host, ipaddress or hoatname, which is having highest priority?

5: What type of the connection exits when client connects to remote database server? Is that TCP or UDP?

6: Is there any provision for database spaaning on multiple diska?

7: How the database recovery is provided in case if the connection between the client and server breaks while the transaction is in process and client
& server are on separate machines/hosts?

Once again thanks in advance,
Namrata.