Re: INSERT ... ON CONFLICT IGNORE (and UPDATE) 3.0

On 04/16/2015 12:18 PM, Andres Freund wrote:
> On 2015-04-15 18:53:15 +0300, Heikki Linnakangas wrote:
>> Hmm, ok, I've read the "INSERT ... ON CONFLICT UPDATE and logical decoding"
>> thread now, and I have to say that IMHO it's a lot more sane to handle this
>> in ReorderBufferCommit() like Peter first did, than to make the main
>> insertion path more complex like this.
>
> I don't like Peter's way much. For one it's just broken. For another
> it's quite annoying to trigger disk reads to figure out what actual type
> of record something is.
>
> If we go that way that's the way I think it should be done: Whenever we
> encounter a speculative record we 'unlink' it from the changes that will
> be reused for spooling from disk and do nothing further. Then we just
> continue reading through the records. If the next thing we encounter is
> a super-deletion we throw away that record. If it's another type of
> change (or even bettter a 'speculative insertion succeeded' record)
> insert it. That'll still require some uglyness, but it should not be too
> bad.

Sounds good to me.

- Heikki