Re: tuple data size and compression

[Tom DalPozzo <t.dalpozzo@xxxxxxxxx>]

2016-12-15 16:23 GMT+01:00 Adrian Klaver <adrian.klaver@xxxxxxxxxxx>:

On 12/15/2016 07:17 AM, Tom DalPozzo wrote:

Hi,

it's not clear to me when tuple data (max 1000 bytes total) get

compressed on disk and when not.

I tried with pg_column_size to find the tuple's size but I get ambiguous

results.

What is the table definition?

Maybe this will help?:

https://www.postgresql.org/docs/9.5/static/storage-toast.html

It seems to work but sometimes the tuples seem compressed and sometime not.

I tried both with constant data and random bytes.

Thanks

Pupillo

--

Adrian Klaver

adrian.klaver@xxxxxxxxxxx

Hi,

definition:   create table stato (id bigint, dati bytea);

then I populate the dati field with  100 bytes.

Pupillo