Re: Fillfactor effectiveness on existing table

On Wed, 11 Feb, 2026, 08:32 Ron Johnson, <ronljohnsonjr(at)gmail(dot)com> wrote:

> On Tue, Feb 10, 2026 at 9:34 PM Durgamahesh Manne <
> maheshpostgres9(at)gmail(dot)com> wrote:
>
>>
>>
>> On Tue, 10 Feb, 2026, 22:58 Ron Johnson, <ronljohnsonjr(at)gmail(dot)com> wrote:
>>
>>> On Tue, Feb 10, 2026 at 11:05 AM David G. Johnston <
>>> david(dot)g(dot)johnston(at)gmail(dot)com> wrote:
>>>
>>>> On Tuesday, February 10, 2026, Durgamahesh Manne <
>>>> maheshpostgres9(at)gmail(dot)com> wrote:
>>>>
>>>>> Hi
>>>>>
>>>>> I added fillfactor with less than 100 to existing table then ran
>>>>> vacuum full to take effect
>>>>>
>>>>> How to ensure the applied fillfactor is working successfully
>>>>>
>>>>> A ratio of hot updates in catalog table should higher than value of
>>>>> n_dead_tup or n_tup_upd? Or what ?
>>>>>
>>>>>
>>>> While free space on the page is necessary for HOT, it is not sufficient.
>>>>
>>>> If you want to prove fillfactor isn’t buggy I’d suggest contriving a
>>>> test case instead inspecting complex real data. A table with a single
>>>> bigint and say 50 fillfactor should be easily visible when inspecting the
>>>> free space of a page in the heap (not sure of the exact query for this
>>>> though). There is a page-inspect contrib extension that provides low-level
>>>> details.
>>>>
>>>
>>> What about pgstattuple.free_space and free_percent?
>>>
>> Hi @Ron <ronljohnsonjr(at)gmail(dot)com>
>> approx_free_space | 13227478672 approx_free_percent | 30.89065723142561
>>
>> Free space can be considered as bloat for non toast table but not for
>> both toast and non toast I believe
>>
>
> 1) Did you vacuum?
> 2) What's the fillfactor?
>
> --
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> Don't boil me, I'm still alive.
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>

@Ron <ronljohnsonjr(at)gmail(dot)com>

Hi
1) vacuum runs daily once and autovacuum triggers for every 1 hour
2) 80

Regards
Durga Mahesh

>