Re: Question on full vacuum clearing waste space

Thank you for the quick response.

I ran the script from https://wiki.postgresql.org/wiki/Show_database_bloat,
which shows "app_event_users" table has 3751936 as wastedbytes.

On Sun, Jun 7, 2020 at 12:32 AM Mohamed Wael Khobalatte <
mkhobalatte(at)grubhub(dot)com> wrote:

>
> On Sat, Jun 6, 2020 at 11:24 PM Wenjun Che <wenjun(at)openfin(dot)co> wrote:
>
>> Hi
>>
>> I am testing full vacuum with pg 10.10 on AWS RDS. I noticed for some
>> tables, the number of waste bytes stays at a few MB after I run full
>> vacuum. I double-checked that there are no long running transactions, no
>> orphaned prepared transactions and no abandoned replication slots.
>>
>> Here is output from full vacuum for one of the tables:
>>
>> VACUUM(FULL, ANALYZE, VERBOSE) app_events_users
>> vacuuming "app_events_users"
>> "app_events_users": found 0 removable, 1198881 nonremovable row versions
>> in 13369 pages
>> analyzing "licensing.app_events_users"
>> "app_events_users": scanned 13369 of 13369 pages, containing 1198881 live
>> rows and 0 dead rows; 30000 rows in sample, 1198881 estimated total rows
>>
>> What else can prevent full vacuum from reclaiming all waste space ?
>>
>> Thank you
>>
>
> What "waste query" are you running? Those tend to be estimates only.
> Vacuum Full clearly did its job from that log you shared.
>

--
Wenjun Che
VP of Engineering | OpenFin
wenjun(at)openfin(dot)co

*Move Fast. Break Nothing.*
www.openfin.co | @openfintech