Re: Significantly larger toast tables on 8.4? - Mailing list pgsql-hackers

From Alex Hunsaker
Subject Re: Significantly larger toast tables on 8.4?
Date
Msg-id 34d269d40901032115v7af81d92vd0fcee7fcec129f8@mail.gmail.com
Whole thread Raw
In response to Re: Significantly larger toast tables on 8.4?  (Philip Warner <pjw@rhyme.com.au>)
List pgsql-hackers
On Sat, Jan 3, 2009 at 21:56, Philip Warner <pjw@rhyme.com.au> wrote:
> Alex Hunsaker wrote:
>> For the record I just imported a production database that sits at
>> about ~20G right now with *zero* size increase (rounding to the
>> nearest gigabyte).  That's with basically the exact same schema just
>> different data.
>>
> Guessing you don't have many plain text rows  > 1M.

Probably not.

>> I don't suppose you could export some random rows and see if you see
>> any size increase for your data?  My gut says you wont see an
>> increase.
>>
>
> Will see what I can do.


Actually assuming they dont have any multibyte chars you should just
be able to do something like the below on your existing database.

-- show anything we save a megabyte on

select die_id, pg_size_pretty(savings) from
( select length(debug) - pg_column_size(debug) as savings, die_id from
fooa) as foo
where savings > 1024*1024 order by savings desc;


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