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From Michael Gentry <blackn...@gmail.com>
Subject Re: Order of operations?
Date Fri, 01 Jul 2016 13:20:02 GMT
Constraints can get even more complex, like Oracle and PostgreSQL (perhaps
others) allow deferrable constraints, which are nice, but MySQL will blow
up immediately if a constraint fails even if it'll be satisfied by the end
of the transaction.


On Fri, Jul 1, 2016 at 9:09 AM, Aristedes Maniatis <ari@maniatis.org> wrote:

> On 1/07/2016 8:57pm, Andrus Adamchik wrote:
> >
> >> On Jun 30, 2016, at 11:04 PM, Aristedes Maniatis <ari@maniatis.org>
> wrote:
> >>
> >> 1. The Cayenne model will need to have additional metadata about
> database indexes and constraints. I've always liked that idea anyway but
> lacked the time to work on it personally. It could open up interesting
> interactions with projects like liquibase [1]
> >
> > We already have information about relationships (that are essentially FK
> constraints). Why do we need to know about indexes for ordering purposes?
>
> I was just thinking about db constraints really. For example, a unique
> index on a field (other than the PK) might need to be taken into
> consideration if you were deleting and creating records. The delete has to
> happen before the create, or they need to be coalesced into a single update.
>
> Ari
>
>
>
> --
> -------------------------->
> Aristedes Maniatis
> GPG fingerprint CBFB 84B4 738D 4E87 5E5C  5EFA EF6A 7D2E 3E49 102A
>

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