Re: Primary keys and composite unique keys(basic question)
| От | Michael Lewis |
|---|---|
| Тема | Re: Primary keys and composite unique keys(basic question) |
| Дата | |
| Msg-id | CAHOFxGr9yhQEN=Fw3A4aqTA+RsdhCVzxfeSCdVzJRq7xW2shuQ@mail.gmail.com обсуждение исходный текст |
| Ответ на | Re: Primary keys and composite unique keys(basic question) (Mohan Radhakrishnan <radhakrishnan.mohan@gmail.com>) |
| Список | pgsql-general |
Etiquette on these lists is to reply in line or below the relevant portion, not top-post with full quoting like default gmail behavior.
On Wed, Mar 31, 2021 at 9:18 AM Mohan Radhakrishnan <radhakrishnan.mohan@gmail.com> wrote:
But we don't search using UUIDs always. Only when data from another distributed serviceis received we need them and in such cases we have to join using them.
I haven't used them so I don't recall exactly, but I believe there is a type of UUID generation which has some leading correlation to time which would help with reducing the random I/O issue that Tom Lane mentioned. A quick search of the archive may lead you to that, or someone else may chime in with the name I expect.
But for local data we can identify another composite unique key. Does PostgreSqlcreate a unique index for us ? What about a FK that references this compositeunique key ? Does it create a FK index ?
It is up to you to create whichever fkeys and indexes you require.
В списке pgsql-general по дате отправления: