Many small queries are efficient in SQLite

Re:Many small queries are efficient in SQLite by kevincox on Tuesday February 16, 2021 @01:23PM (#26157025)

This sounds like a problem with Postfix or Dovecot. Postfix shouldn't ack or Dovecot shouldn't delete the email until it is safely stored.

That being said there are many use cases where having high availability is critical and in the face of multiple writers SQLite isn't the best option for that.

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Re:Many small queries are efficient in SQLite by lisper on Tuesday February 16, 2021 @01:52PM (#26157347)

I don't think this is a multiple-writer problem. Postfix is only reading. I am running a milter that is writing, but I control the code for that so I have it set up to retry if it fails. So the error is being generated by postfix itself, and so it must be happening on a read (because that is all postfix does).

I was hoping to find some kind of global switch that would make sqlite always wait for locks rather than throwing an error. But I've scoured the web for such a solution without success :-(

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Re:Many small queries are efficient in SQLite by samatman on Tuesday February 16, 2021 @05:15PM (#26159442)

There is no such thing, to my knowledge.

What can be done is registering a busy callback:

https://www.sqlite.org/c3ref/busy_handler.html

I don't understand enough about your specific problem to know if this will actually help you, just sharing a tidbit I encountered working on a comparable issue.

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