I believe functions in Postgres follow a late binding approach and hence
nested function dependencies are resolved using search_path at run time.
This way a user can override nested functions in its schema and change the
behaviour of wrapper functions. However, a more serious issue is when
"Given the size of toasted data, the overhead is unlikely to be a
significant overhead. It's much more an issue for the main table, where
narrow rows are common."
Completely agree, row size should not be a big concern for toast tables.
However write amplification will happen with vacuum freeze
Another point that currently manual VACUUM job does cleanup/freeze on
primary table first and then toast table. It looks easy pick to possibly
have a configurable parameter to run it on both the tables in parallel.
On Sat, Nov 20, 2021 at 12:15 AM Virender Singla
wrote:
> Why do Toast tab
Why do Toast tables have it's own visibility map and xmin, xmax columns etc?
Isn't it increasing row size in a toast table and adding more complexity?
Ideally all the vacuum cleanup on a TOAST can be done based on Primary
table xmin,xmax and VM info. Yes, that makes any cleanup on TOAST to be
uum freeze.
On Tue, Apr 13, 2021 at 6:02 PM Masahiko Sawada
wrote:
> On Tue, Apr 13, 2021 at 1:51 PM Virender Singla
> wrote:
> >
> > Thanks Masahiko for the response.
> >
> > "What is
> > the use case where users want to freeze fewer transactio
transactions because currently there is
no way to know what block/tuple contains which transaction id. If there is
a way then it would be easier to directly freeze those tuples quickly and
advance the relfrozenxid for the table.
On Tue, Apr 13, 2021 at 7:52 AM Masahiko Sawada
wrote:
> On Mon,
Hi Postgres Community,
Regarding anti wraparound vacuums (to freeze tuples), I see it has to scan
all the pages which are not frozen-all (looking at visibility map). That
means even if we want to freeze less transactions only (For ex - by
increasing parameter vacuum_freeze_min_age to 1B), still
t | index | postgres | test | 282 MB |
On Fri, May 8, 2020 at 1:50 PM Virender Singla
wrote:
> Why Postgres default FILLFACTOR for table is 100 and for Index is 90.
>
> Although Oracle is having completely different MVCC architecture, it uses
> default 90 for table and 100 for Index (
Why Postgres default FILLFACTOR for table is 100 and for Index is 90.
Although Oracle is having completely different MVCC architecture, it uses
default 90 for table and 100 for Index (exact reverse of Postgres)
Postgres blocks needed more spaces for row update compares to Oracle
(because Oracle
2019 at 10:16 PM Tom Lane wrote:
> Virender Singla writes:
> > Currently I see the vacuum behavior for a table is that, even if a long
> > running query on a different table is executing in another read committed
> > transaction.
> > That vacuum in the 1st transaction
Currently I see the vacuum behavior for a table is that, even if a long
running query on a different table is executing in another read committed
transaction.
That vacuum in the 1st transaction skips the dead rows until the long
running query finishes.
Why that is the case, On same table long
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