Re: READ UNCOMMITTED in postgres

Stephen Frost <[email protected]> Wed, 18 Dec 2019 18:20:03 -0500

Newsgroups	gmane.comp.db.postgresql.general
Message-ID	<[email protected]>

Greetings,

* Matthew Phillips ([email protected]) wrote:
> With the current READ UNCOMMITTED discussion happening on pgsql-hackers
> [1], It did raise a question/use-case I recently encountered and could not
> find a satisfactory solution for. If someone is attempting to poll for new
> records on a high insert volume table that has a monotonically increasing
> id, what is the best way to do it? As is, with a nave implementation, rows
> are not guaranteed to appear in monotonic order; so if you were to keep a
> $MAX_ID, and SELECT WHERE p_id > $MAX_ID, you would hit gaps. Is there a
> clean way to do this? I've seen READ UNCOMMITTED used for this with DB2.

There's the LISTEN/NOTIFY system, which at a high level is a better
approach than using a polling system.

Thanks,

Stephen

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