Re: High concurrency same row (inventory)

MichaelDBA <michaeldba@sqlexec.com>

From: MichaelDBA <MichaelDBA@sqlexec.com>
To: Jean Baro <jfbaro@gmail.com>
Cc: Michael Lewis <mlewis@entrata.com>, Rick Otten <rottenwindfish@gmail.com>, pgsql-performance@lists.postgresql.org
Date: 2019-07-30T01:13:00Z
Lists: pgsql-performance
Looks like regular updates not HOT UPDATES

Jean Baro wrote on 7/29/2019 8:26 PM:
> image.png
>
> The dead tuples goes up at a high ratio, but then it gets cleaned.
>
> if you guys need any further information, please let me know!
>
>
>
> On Mon, Jul 29, 2019 at 9:06 PM Jean Baro <jfbaro@gmail.com 
> <mailto:jfbaro@gmail.com>> wrote:
>
>     The UPDATE was something like:
>
>     UPDATE bucket SET qty_available = qty_available + 1 WHERE
>     bucket_uid = 0940850938059380590
>
>     Thanks for all your help guys!
>
>     On Mon, Jul 29, 2019 at 9:04 PM Jean Baro <jfbaro@gmail.com
>     <mailto:jfbaro@gmail.com>> wrote:
>
>         All the failures come from the Bucket Table (see image below).
>
>         I don't have access to the DB, neither the code, but last time
>         I was presented to the UPDATE it was changing (incrementing or
>         decrementing) *qty_available*, but tomorrow morning I can be
>         sure, once the developers and DBAs are back to the office. I
>         know it's quite a simple UPDATE.
>
>         Table is called Bucket:
>         {autovacuum_vacuum_scale_factor=0.01}
>
>         Bucket.png
>
>
>         On Mon, Jul 29, 2019 at 3:12 PM Michael Lewis
>         <mlewis@entrata.com <mailto:mlewis@entrata.com>> wrote:
>
>             Can you share the schema of the table(s) involved and an
>             example or two of the updates being executed?
>