Στις 15/7/24 22:55, ο/η Ron Johnson έγραψε:
On Mon, Jul 15, 2024 at 3:28 PM Christophe Pettus <x...@thebuild.com>
wrote:
> On Jul 15, 2024, at 12:06, Sarkar, Subhadeep
<subhadeepsar...@kpmg.com> wrote:
>
[snip]
> • In the Community edition of PostgreSQL is it possible to
setup a cluster where all the nodes are able to concurrently
read-write the underlying database image using NATIVE features
(i.e. without using any extensions or external components or usage
of Kubernetes/Dockers).
[snip]
No product, either commercial or open-source, provides the last
one (read-write shared storage), although there are commercial
products that provide for a shared-storage model single-writer,
multiple-reader model (for example, Amazon Aurora).
This "lack of products" puzzles me, because DEC was doing this with
VAX (then Alpha and Itanium) clusters 40 years ago via a Distributed
Lock Manager integrated deep into VMS. Their Rdb and (CODASYL) DBMS
products used those functions extensively.
IMHO IBM did something similar with their shared DASDi back in 70s+.
There was serialization mechanism enabling concurrent writes to data
sets (meaning files). Not to mention IBM had great VM technology back in
the day.
(In the late 1990s, they sold the DLM code to Oracle, which is where
RAC comes from.)
It was shared-disk, multiple-writer, because the DLM allowed for
locking at the row level. Thus, a half dozen cluster nodes could hold
write locks on different rows on the same data page.
--
Achilleas Mantzios
IT DEV - HEAD
IT DEPT
Dynacom Tankers Mgmt (as agents only)
