To what extent can MySQL clients interact with servers of different
versions?

In particular, if I link an Apache PHP module with the client libraries
for MySQL version 5.0.51, will I be able to use it to connect to a
version 4.1.22 server?

I ask this because I am running a web hosting service, and have a number
of different users using MySQL 4.1 servers via PHP from Apache. I need
to them to convert their servers to MySQL 5.

If the mixed-version set-up described above is OK, I could conveniently
upgrade them all to the same new PHP module _before_ upgrading the servers
individually.

If the mixed-version set-up is not OK, I have a more challenging task.
I have to keep the clients and servers in step.

P.S. I am more familiar with Oracle than with MySQL. I know that an
Oracle 10 client can be used with with servers going back at least to
Oracle 8.

--
Charles Jardine - Computing Service, University of Cambridge
cj10@cam.ac.uk Tel: +44 1223 334506, Fax: +44 1223 334679

Charles Jardine wrote:
> To what extent can MySQL clients interact with servers of different
> versions?
>
> In particular, if I link an Apache PHP module with the client libraries
> for MySQL version 5.0.51, will I be able to use it to connect to a
> version 4.1.22 server?
>
> I ask this because I am running a web hosting service, and have a number
> of different users using MySQL 4.1 servers via PHP from Apache. I need
> to them to convert their servers to MySQL 5.
>
> If the mixed-version set-up described above is OK, I could conveniently
> upgrade them all to the same new PHP module _before_ upgrading the servers
> individually.
>
> If the mixed-version set-up is not OK, I have a more challenging task.
> I have to keep the clients and servers in step.
>
> P.S. I am more familiar with Oracle than with MySQL. I know that an
> Oracle 10 client can be used with with servers going back at least to
> Oracle 8.
>

Our client-server protocol has not changed much, if at all, in a long
while. You should be quite safe using a 5.x-based client library to talk
to a 4.1 and even a 3.x server.

--
Shawn Green, Support Engineer
MySQL Inc., USA, www.mysql.com
Office: Blountville, TN
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