Re: Incremental backup

On 10/28/21 11:48, Ron wrote:
> On 10/28/21 1:00 PM, Adrian Klaver wrote:
>> On 10/28/21 10:51, Ron wrote:
>>

> Not doable in Postgresql because WAL files are global to cluster. I've
> read multiple times that will not be changed.

Yet somehow logical replication does it:

https://www.postgresql.org/docs/14/logical-replication-architecture.html

"
Logical replication is built with an architecture similar to physical
streaming replication (see Section 27.2.5). It is implemented by
“walsender” and “apply” processes. The walsender process starts logical
decoding (described in Chapter 49) of the WAL and loads the standard
logical decoding plugin (pgoutput). The plugin transforms the changes
read from WAL to the logical replication protocol (see Section 53.5) and
filters the data according to the publication specification. The data is
then continuously transferred using the streaming replication protocol
to the apply worker, which maps the data to local tables and applies the
individual changes as they are received, in correct transactional order.
"

https://www.postgresql.org/docs/14/logical-replication.html

"The typical use-cases for logical replication are:

Sending incremental changes in a single database or a subset of a
database to subscribers as they occur.
...
"

>
> PgBackRest does full and incremental backups, plus captures WAL files,
> but globally to a cluster.
>
> --
> Angular momentum makes the world go 'round.

--
Adrian Klaver
adrian(dot)klaver(at)aklaver(dot)com