Re: Increased storage size of jsonb in pg15

On 12/28/23 09:13, Sean Flaherty wrote:
> Follow-up:
> Working with AWS, we found that starting in RDS Postgres 15, the
> default_toast_compression parameter is set to use lz4 compression
> instead of pglz.  This resulted in the increased json storage size we
> were seeing.
>
> I have been able to reproduce the increased storage size on RDS Postgres
> and using my local docker instance of postgres 15.5 by changing the
> local default_toast_compression value in postgresql.conf.
>
> I have attached the test script we use to create a table, insert some
> test records and a query to test the JSON data size on disk.

I can confirm I see the same results using Postgres 16 installed from
the PGDG repo on Ubuntu 22.04. That the lz4 data size is greater then
the pglz data size.

>
>
> Kind regards,
> Sean
>


--
Adrian Klaver
adrian.klaver@aklaver.com