Re: Inaccurate description of UNION/CASE/etc type selection
| От | David G. Johnston |
|---|---|
| Тема | Re: Inaccurate description of UNION/CASE/etc type selection |
| Дата | |
| Msg-id | CAKFQuwY_TRhxKvnf26L0ZQpYm56Y7__WL7GhR0VGg8AX90HTJw@mail.gmail.com обсуждение исходный текст |
| Ответ на | Re: Inaccurate description of UNION/CASE/etc type selection ("David G. Johnston" <david.g.johnston@gmail.com>) |
| Ответы |
Re: Inaccurate description of UNION/CASE/etc type selection
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| Список | pgsql-docs |
On Sun, Aug 16, 2020 at 5:58 PM David G. Johnston <david.g.johnston@gmail.com> wrote:
5. If the first non-unknown type is a preferred type it is chosen, otherwise it is made a candidate, and then,6. each subsequent type is compared to the current candidate, with a new candidate being chosen only when there exists a non-mutal implicit cast to the new type.6a. If at any point a preferred type is made a candidate then it will be chosen.
More concisely:
Make the first input type a candidate type. Each subsequent input type is compared to the current candidate, with a new candidate being chosen only when there exists a non-mutal implicit cast to the new type. If at any point a preferred type is made a candidate then it will be chosen.
In my original the whole if/otherwise in 5 is pointless given the presence of 6a.
David J.
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