On 10/28/21 2:06 PM, Adrian Klaver wrote:
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
Scans the (global) WAL data for only the that portion from the relevant
database?
If so, definitely not the same as having per-database WAL files.
Just as importantly, replication is not, and never will be, a substitute for
backups.
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.
...
"
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