Re: tuple data size and compression

2016-12-15 16:23 GMT+01:00 Adrian Klaver <adrian(dot)klaver(at)aklaver(dot)com>:

> 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(dot)klaver(at)aklaver(dot)com

Hi,
definition: create table stato (id bigint, dati bytea);
then I populate the dati field with 100 bytes.
Pupillo