Guy Rouillier wrote:
> John R Pierce wrote:
>> Guy Rouillier wrote:
>>> janaka priyadarshana wrote:
>>>> hi all
>>>>
>>>>
>>>> my database server is running on one machine and the application
>>>> is running on another machine(simple java application use to access
>>>> the database).
>>>>
>>>> so i want to know, what is the protocol that use to communicate
>>>> between those two applications...?
>>>
>>> JDBC.
>>>
>>
>> not exactly. JDBC is the API your app uses to access the
>> database. the JDBC class libraries for postgres on the client
>> system will use postgres's native protocol to talk to the PG Server
>> (default of 5432/tcp)
>
> Well, with any network communication, there are multiple layers of
> protocols involved. You took it one layer below JDBC, but we could
> keep on going down to the physical layer link protocol. Since the
> O.P. was asking on a JDBC mailing list, I assumed he was interested in
> that layer.
>
Note the difference between the Protocol and the API.
Correct answer, IMHO, would be that PostgreSQL JDBC driver is Type 4 and
it will use same protocol as native client. To be noted, that is does
not contain Type 2 driver and so can communicate via TCP/IP only, even
when connecting to local host. Also there is an option to use SSL
secured connection, but I can't tell any more (how to enable this)
because've never used this mode. There may be some Java-specific SSL
problems (like specifying keyring).