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