Re: Version number for pg_control

On 7/15/16 5:47 PM, Alvaro Herrera wrote:
> Tom Lane wrote:
>> While researching a pgsql-general question, I noticed that commit
>> 73c986adde5d73a5e2555da9b5c8facedb146dcd added several new fields
>> to pg_control without bothering to touch PG_CONTROL_VERSION.  Thus,
>> PG_CONTROL_VERSION is still "942" even though the file contents
>> are not at all compatible with 9.4.
> 
> Oh crap :-(
> 
>> It's way too late to do anything about this in 9.5.  I wonder though
>> if we should advance PG_CONTROL_VERSION now, presumably to "960",
>> so that at least as of 9.6 the format is correctly distinguished
>> from the 9.4-era format.  Or will that just make things even more
>> confusing, given that 9.5 is what it is?
> 
> I can't quite make up my mind about it.  It seems pointless to change
> it now, but at the same time it seems wrong to let it continue to be
> unchanged from 9.4.
> 
> I slightly lean towards changing it in 9.6.

+1 for changing it.  However, I don't think it's such a big deal since
each version since 8.3 (at least) has had a unique catalog version.

Maybe this would affect pg_controldata or other supporting utilities but
the server itself should not be affected since it also checks the
catalog version.

-- 
-David
david@pgmasters.net