How many no. of clients can access database simultaneously?

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?

It depends on a lot of things. Hardware/OS configuration being at the top of
the list. I'm sure there is no hard coded limit to the number of connections
in PG so it's what ever your machine can support.

2: What is the recovery mechanism provided for PostgreSQL? Is there any

provision for comma separated records or file?

Aside from the WAL log, you can dump databases to flat files for later
import.

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

DATESTYLE and TIMESTAMP?

DATESTYLE can be set through an environment variable or SET in a PG session
(I think).

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?

Huh? How are you providing both?

5: What type of the connection exits when client connects to remote

database server? Is that TCP or UDP?

TCP

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

I would think this would be more of an operating system's job but PG stores
databases in directories on the file system, I guess if those directories
were mounted on different disks it would work -- *shrug* don't take my word
for it though.

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?

I assume that the transaction rolls back.

-Mitch

Namrata writes:

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

The compiled-in default is 1024, the run-time default is 32. Both can be
changed to a couple of million if you have the memory. (Not that an OS
will usually support that many processes.)

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

Make regular backups. ;-)

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

No, but there's an SQL interface that you can call from C or C++.

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?

IP address

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

TCP

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

Not within PostgreSQL, but you can use a logical volumen manager in your
operating system.

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?

Transaction is rolled back.

--
Peter Eisentraut peter_e@gmx.net http://funkturm.homeip.net/~peter