Re: Usage of epoch in txid_current - Mailing list pgsql-hackers

From Andres Freund
Subject Re: Usage of epoch in txid_current
Date
Msg-id F6FA5A92-FAC7-4F45-8923-75859B5EAB63@anarazel.de
Whole thread Raw
In response to Re: Usage of epoch in txid_current  (Michael Paquier <michael@paquier.xyz>)
List pgsql-hackers

On February 4, 2019 6:43:44 AM GMT+01:00, Michael Paquier <michael@paquier.xyz> wrote:
>On Sun, Feb 03, 2019 at 10:58:02PM +1100, Thomas Munro wrote:
>> If there are no objections, I'm planning to do a round of testing and
>> commit this shortly.
>
>Hm.  That looks sane to me at quick glance.  I am a bit on the edge
>regaring the naming "FullTransactionId", which is actually a 64-bit
>value with a 32-bit XID and a 32-bit epoch.  Something like
>TransactionIdWithEpoch or EpochTransactionId sounds a bit better to
>me.  My point is that "Full" is too generic for that.

I'm not a fan of names with epoch in it - these are the real transaction IDs now. Conflating them with the until-now
inferredepochs sounds like a bad idea to me. We IMO should just treat the new type as a 64bit uint, and the 32bit as a
truncatedversion. Like, we could just add 64 as a prefix. 

Andres
--
Sent from my Android device with K-9 Mail. Please excuse my brevity.


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