Re: Note about upcoming instability in FE/BE protocol

Did you ever get my post about making the BE protocol implemented as a 
shared library?

Tom Lane wrote:

>I am about to start committing changes to CVS tip to implement the
>planned FE/BE protocol changes.  My plan is to do this a bit at a time,
>since I don't want to get far out of sync with CVS.  This means that the
>actual protocol supported by CVS tip is going to change little by
>little.  Yesterday's libpq may or may not talk to today's server.
>
>To try to keep people from wasting time chasing version-skew problems
>while this goes on, I have devised the following plan.  The server and
>libpq will claim to speak protocol numbers 3.100, 3.101, 3.102, etc,
>changing each time a visible change is committed.  There is also a
>temporary hack in postmaster.c that will reject connections from clients
>claiming to speak 3.anything-other-than-postmaster's-version.  If you
>have an out-of-sync libpq, you will get something like
>FATAL: unsupported frontend protocol 3.110: server supports 1.0 to 3.109
>or
>FATAL: Your development libpq is out of sync with the server
>
>After the dust settles, I'll reset the protocol version number to 3.0
>for release.
>
>Note that this should only affect libpq.  Other clients may continue to
>speak protocol 2.0 while this is going on, and that should not change.
>In emergency you should be able to use a 7.3 copy of libpq.so to talk to
>the CVS-tip server.
>
>            regards, tom lane
>
>
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