Re: MVCC and all that...
| От | Merlin Moncure |
|---|---|
| Тема | Re: MVCC and all that... |
| Дата | |
| Msg-id | CAHyXU0ysP0AroxGVrCPzUyXuTxi_we=v-bNRtns82nf3rMrGxw@mail.gmail.com обсуждение исходный текст |
| Ответ на | Re: MVCC and all that... (Ron Johnson <ronljohnsonjr@gmail.com>) |
| Список | pgsql-general |
On Tue, Sep 9, 2025 at 7:11 PM Ron Johnson <ronljohnsonjr@gmail.com> wrote:
On Tue, Sep 9, 2025 at 8:41 PM Justin <zzzzz.graf@gmail.com> wrote:
On autonomous transactions we have procedures now that allow transactions inside of transactions that can be committed and rollbacked. that has been around for several years now.
[snip]
anonymous functions in PG have several limitation not just input arguments (not sure i see the need for that)Aren't transience and "ad hockery" the whole point of anonymous procedures? Thus, I don't see the point of passing them parameters, either.(When I do need something similar, I build the DO block as a bash string variable with environment variables as "parameters", and then execute it via psql -c "$sql" More like a template, TBH. It's great for purging old data from tables, since I can bypass records who's DELETE statements fail due to a FK constraint.
IMO, you can't equate procedures to autonomous transactions. The only way to do AT in a procedure today is with dblink if you are limited to core/contrib. pg_background can do them, as can my library, pgasync. I would humbly state it's a very high quality library to deal with them in a general way :).
Autonomous transactions are basically threading at the SQL level. The classic use case for them is to emit log records while you're processing some bigger transaction, so that if/when rollback occurs you have some evidence of processing. There are many, many other use cases for them however if you are deep into backend programming.
I will say that the stored procedure COMMIT feature made this library possible as before, it was not possible to have long running processes in the database at the SQL level.
Personally, rather than having explicit syntax supporting AT (or at least, in addition to-), I would like to see the dblink library boned up; we ought to have asynchronous connections, and a multi connection dblink_poll() to avoid the dblink_is_busy polling loop.
Getting back to firebase, I suppose we ought not to treat the article author too harshly. There's nothing wrong with advocating for your solution although a more balanced treatment might have been more compelling.
merlin
В списке pgsql-general по дате отправления: