Re: [PATCH] SQL assertions prototype

Peter Eisentraut <peter_e(at)gmx(dot)net> schrieb:
>On 12/18/13, 2:22 PM, Andres Freund wrote:
>> It would only force serialization for transactions that modify tables
>> covered by the assert, that doesn't seem to bad. Anything covered by
>an
>> assert shoulnd't be modified frequently, otherwise you'll run into
>major
>> performance problems.
>
>I think that makes sense. If you want to use assertions, you need to
>run in serializable mode, otherwise you get an error if you modify
>anything covered by an assertion.
>
>In the future, someone could enhance this for other isolation levels,
>but as Josh has pointed out, that would likely just be reimplementing
>SSI with big locks.

SSI only actually works correctly if all transactions use SSI... I am not sure if we can guarantee that the subset we'd require'd be safe without the read sie using SSI.

Andres

--
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Andres Freund http://www.2ndQuadrant.com/
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