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. Kind regards, Sean On Fri, Dec 15, 2023 at 1:56 PM Adrian Klaver <adrian.kla...@aklaver.com> wrote: > On 12/15/23 12:43, Sean Flaherty wrote: > > We did a little more digging on our side, which I apologize for not > > doing beforehand. > > > > We wrote a script to create a simple table with a jsonb column, inserted > > some json data into the column and then used *pg_column_size* to test > > the size of the jsonb data column. > > > > We ran the script against local docker versions of postgres 14.8 and > > 15.5 and saw that the data in the jsonb column was the same size. > > > > We then ran the script on AWS RDS Postgres and saw a size difference for > > the same json data between versions 14.8 and 15.4 (we also saw the > > larger size on RDS postgres 15.5 and 16.1). > > This points at RDS Postgres being the issue. Since that is behind the > AWS curtain, you will need to contact AWS technical support for > information on what changed. > > > > > *Version* *size (kb)* *notes * > > RDS Postgres-14.8 1587 (the same size we were seeing > locally) > > RDS Postgres-15.4 2112 > > > > > > Thank you for your prompt responses and assistance. > > > > If you are curious, I can share the script we used with you. > > > > > > Kind regards, > > Sean > > > -- > Adrian Klaver > adrian.kla...@aklaver.com > >
<<attachment: jsonDataStorageTestScript.zip>>
