Re: Hot Standby (v9d)

Heikki Linnakangas wrote:
> Simon Riggs wrote:
>> If you have a serializable transaction with subtransactions that suffers
>> a serializability error it only cancels the current subtransaction. That
>> means it's snapshot is still valid and can be used again. By analogy, as
>> long as a transaction does not see any data that is inconsistent with
>> its snapshot it seems OK for it to continue. So I think it is correct.
>
> Yeah, you're right. How bizarre.

It was argued this way to me way back when subtransactions were written.
Originally I had written it in such a way as to abort the whole
transaction, on the rationale that if you're blindly restarting the
subtransaction after a serialization error, it would result in a (maybe
infinite) loop.  I think the reason it only aborts the subxact is that
that's what all other errors do, so why would this one act differently.

Hmm, now that I think about it, I think it was deadlock errors not
serialization errors ...

-- 
Alvaro Herrera                                http://www.CommandPrompt.com/
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