Re: Missing FIN_CRC32 calls in logical replication code

On 11/11/2014 06:55 PM, Andres Freund wrote:
> On 2014-11-03 21:58:51 +0200, Heikki Linnakangas wrote:
>> PS. I find the name "ReplicationSlotOnDiskDynamicSize" confusing, as it is
>> in fact a fixed size struct. I gather it's expected that the size of that
>> part might change across versions, but by that definition nothing is
>> constant.
>
> Well, the idea is that the 'constant' part is version independent. The
> part following afterwards (dynamic) can differ based on the 'version'
> struct member. The reason is that that allows files from older releases
> to be read after a pg_upgrade.
>
> If you have suggestions for better names.

(It's a bit late, I know, but...)

I would actually suggest using the 'magic' field as the version 
identifier. Increment it by one on every version change. It would be 
handy to have the version ID as the first field in the file.

- Heikki