Re: Simplifying the interface of UpdateMinRecoveryPoint

On 07/13/2016 04:25 PM, Michael Paquier wrote:
> On Wed, Jul 13, 2016 at 8:27 PM, Amit Kapila <amit.kapila16@gmail.com> wrote:
>> On Wed, Jul 13, 2016 at 9:19 AM, Michael Paquier
>> <michael.paquier@gmail.com> wrote:
>>> Hence why not simplifying its interface and remove the force flag?
>>
>> One point to note is that the signature and usage of
>> UpdateMinRecoveryPoint() is same as it was when it got introduced in
>> commit-cdd46c76.  Now the only reasons that come to my mind for
>> introducing the force parameter was (a) it looks cleaner that way to
>> committer (b) they have some usecase for the same in mind (c) it got
>> have overlooked.  Now, if it got introduced due to (c), then your
>> patch does the right thing by removing it.  Personally, I feel
>> overloading the parameter for multiple purposes makes code less
>> maintainable, so retaining as it is in HEAD has some merits.
>
> There is no way to tell what that is, but perhaps Heikki recalls
> something on the matter. I am just adding him in CC.

No, I don't remember. Maybe the function originally used the 
caller-supplied 'lsn' value as the value to force-update 
minRecoveryPoint to. Or I anticipated that some callers might want to do 
that in the future.

If we were to do this, it might be better to still have a 'force' 
variable inside the function, to keep the if()s slighltly more readable, 
like:
  bool force = XLogRecPtrIsInvalid(lsn);

But even then, I don't think this makes it really any more readable 
overall. Not worse either, but it's a wash. I'll just mark this as 
rejected in the commitfest, let's move on.

- Heikki