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Re: Regarding fillfactor use case for only delete ops
3+ messages / 3 participants
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* Re: Regarding fillfactor use case for only delete ops
@ 2025-06-06 13:59  Ron Johnson <[email protected]>
  0 siblings, 1 reply; 3+ messages in thread

From: Ron Johnson @ 2025-06-06 13:59 UTC (permalink / raw)
  To: Laurenz Albe <[email protected]>; +Cc: Durgamahesh Manne <[email protected]>; pgsql-general <[email protected]>

On Fri, Jun 6, 2025 at 8:57 AM Laurenz Albe <[email protected]>
wrote:

> On Fri, 2025-06-06 at 14:10 +0530, Durgamahesh Manne wrote:
> > Can we generate a fill factor for tables that have delete ops ?
> >
> > Does the fill factor really work and help to minimize the bloat for
> tables that have delete ops?
> >
> > I have parent table with weekly partitions So for every week 50 to 60 gb
> of bloat generates and autovacuum params already in place for child tables
>
> Nothing can ever avoid bloat caused by DELETE, except partitioning in a
> way that you can drop a partition rather than running DELETE.
>
>
Laurenz,

Isn't the fill factor aimed at reducing bloat during updates of HOT tables?

-- 
Death to <Redacted>, and butter sauce.
Don't boil me, I'm still alive.
<Redacted> lobster!


^ permalink  raw  reply  [nested|flat] 3+ messages in thread

* Re: Regarding fillfactor use case for only delete ops
@ 2025-06-06 23:04  Durgamahesh Manne <[email protected]>
  parent: Ron Johnson <[email protected]>
  0 siblings, 1 reply; 3+ messages in thread

From: Durgamahesh Manne @ 2025-06-06 23:04 UTC (permalink / raw)
  To: Ron Johnson <[email protected]>; +Cc: Laurenz Albe <[email protected]>; pgsql-general <[email protected]>

On Fri, Jun 6, 2025 at 7:29 PM Ron Johnson <[email protected]> wrote:

> On Fri, Jun 6, 2025 at 8:57 AM Laurenz Albe <[email protected]>
> wrote:
>
>> On Fri, 2025-06-06 at 14:10 +0530, Durgamahesh Manne wrote:
>> > Can we generate a fill factor for tables that have delete ops ?
>> >
>> > Does the fill factor really work and help to minimize the bloat for
>> tables that have delete ops?
>> >
>> > I have parent table with weekly partitions So for every week 50 to 60
>> gb of bloat generates and autovacuum params already in place for child
>> tables
>>
>> Nothing can ever avoid bloat caused by DELETE, except partitioning in a
>> way that you can drop a partition rather than running DELETE.
>>
>>
> Laurenz,
>
> Isn't the fill factor aimed at reducing bloat during updates of HOT tables?
>
> --
> Death to <Redacted>, and butter sauce.
> Don't boil me, I'm still alive.
> <Redacted> lobster!
>


Hi

I believe that fill factor works exclusively for updates of HOT tables  but
not for delete ops

Regards,
Durga Mahesh


^ permalink  raw  reply  [nested|flat] 3+ messages in thread

* Re: Regarding fillfactor use case for only delete ops
@ 2025-06-06 23:14  Adrian Klaver <[email protected]>
  parent: Durgamahesh Manne <[email protected]>
  0 siblings, 0 replies; 3+ messages in thread

From: Adrian Klaver @ 2025-06-06 23:14 UTC (permalink / raw)
  To: Durgamahesh Manne <[email protected]>; Ron Johnson <[email protected]>; +Cc: Laurenz Albe <[email protected]>; pgsql-general <[email protected]>

On 6/6/25 16:04, Durgamahesh Manne wrote:
> 

> 
> Hi
> 
> I believe that fill factor works exclusively for updates of HOT tables  
> but not for delete ops

 From here:

https://www.postgresql.org/docs/current/sql-createtable.html

"fillfactor (integer)

     The fillfactor for a table is a percentage between 10 and 100. 100 
(complete packing) is the default. When a smaller fillfactor is 
specified, INSERT operations pack table pages only to the indicated 
percentage; the remaining space on each page is reserved for updating 
rows on that page. This gives UPDATE a chance to place the updated copy 
of a row on the same page as the original, which is more efficient than 
placing it on a different page, and makes heap-only tuple updates more 
likely. For a table whose entries are never updated, complete packing is 
the best choice, but in heavily updated tables smaller fillfactors are 
appropriate. This parameter cannot be set for TOAST tables.
"

So it increases the chances of HOT updates, but is not restricted to them.

> 
> Regards,
> Durga Mahesh
> 

-- 
Adrian Klaver
[email protected]







^ permalink  raw  reply  [nested|flat] 3+ messages in thread


end of thread, other threads:[~2025-06-06 23:14 UTC | newest]

Thread overview: 3+ messages (download: mbox mbox.gz follow: Atom feed)
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2025-06-06 13:59 Re: Regarding fillfactor use case for only delete ops Ron Johnson <[email protected]>
2025-06-06 23:04 ` Durgamahesh Manne <[email protected]>
2025-06-06 23:14   ` Adrian Klaver <[email protected]>

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