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.