Subject: Re: Insert records in the tavke only if they are not exist

From: "David G. Johnston" <[email-masked]>
Date: Fri, 6 Dec 2024 20:55:00 -0700

On Friday, December 6, 2024, Igor Korot <[email-masked]> wrote:
>
> When my application starts up, ot creates some tables and insert records
> in them.
>
> When the app starts for the second time it should check if the tables and
> the records in them are exist and skip the process.
>
> Everything is good, except what if I have a connection from 2 different
> users?
>
> I can run this inside transaction, but will this be enough? Will stating
> transaction lock the DB and the second user will wait for transaction to
> complete?
>
>
Seems like letting the create table fail would be a reliable way to
determine what is happening.  But this procedure overall just seems better
avoided.  Can’t you just run an installer/updater separate from running the
application?

David J.

---

From: Igor Korot <[email-masked]>
Date: Fri, 6 Dec 2024 22:02:22 -0600

Hi, Dvid,

> avoided.  Can’t you just run an installer/updater separate from running the

Interesting idea bout the installer.
Except those tables will contain some additional info about the schema and
the application.

So if I create/remove new table, either in my app or from psql the record
will need to be inserted/deleted.

Thank you.