Re: does refreshing materialized view make the database bloat?

On Sat, Jan 14, 2023 at 11:49 AM David G. Johnston <
david(dot)g(dot)johnston(at)gmail(dot)com> wrote:

> On Friday, January 13, 2023, jian he <jian(dot)universality(at)gmail(dot)com> wrote:
>
>>
>> Once we have the diff table, we perform set-based DELETE and INSERT
>>> operations against the materialized view, and discard both temporary
>>> tables.
>>>
>>
>> Here the temporary tables are "discard" meaning the temporary tables are
>> deleted and the temporary tables' spaces are reclaimed immediately?
>> Or the temporary tables are deleted and the spaces will be reclaimed by
>> another mechanism?
>>
>> simplify:does refreshing materialized view make the database bloat.
>>
>>
> The materialized view itself bloats. The temp tables are removed
> immediately (the “drop table” docs don’t say this explicitly though it the
> most logical behavior and implied by the fact it takes an access exclusive
> lock).
>
> David J.
>
>
Hi,
why the materialized view itself bloats. If no refresh then no bloat right?
If fresh then set based delete operation will make materialized view bloat?
I also found the same question online.
https://dba.stackexchange.com/questions/219079/bloat-on-materialized-views
Unfortunately nobody answered...