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From: Kristjan Mustkivi <sonicmonkey@gmail.com>
Date: Sun, 19 Apr 2026 14:43:47 +0300
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Subject: Re: table bloat very fast and free space can not be reused
To: James Pang <jamespang886@gmail.com>
Cc: pgsql-performance@lists.postgresql.org
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On Sun, Apr 19, 2026 at 4:28=E2=80=AFAM James Pang <jamespang886@gmail.com>=
 wrote:
>
> experts:
>      source database v14 ,  pglogical extension 2.4.5 replication to new =
17, source table very frequent UPDATEs /DELETES /INSERTS and has two text a=
nd jsonb. in source database, application update/delete/insert through SQL,=
 table size did not increased quickly. but in target pg v17 , by pglogical =
apply, we found table increased very quickly , table size got doubled in da=
ys.
>     Vacuum analyze did not help , only vacuum full can help. pgstattuple =
show most of space are free space , that much more than source.  it looks l=
ike these replicate DML always asking new pages instead of reuse existing f=
reespace.

Hi,

We have had the exact same problem in the past - a large json column
getting very frequent updates (hundreds even thousand per minute) on
the source and the replica side table bloating up. No amount of tuning
attempts made any difference (conversion of json to text, different
table specific autovacuum settings etc). Eventually, the table was
taken out of the replication and later on made UNLOGGED which also
freed up a giant swathes of storage from WAL written. Such design was
then called an antipattern and has not been allowed since.

With best regards,

Kristjan