Expanded Examples and Use Cases
===============================

While PGD Essential delivers the core functionality needed to get high
availability and/or disaster recover use cases up and running quickly,
there are many advanced use cases that can be implemented with PGD
Essential. This section provides examples of how to implement some of
these advanced use cases.

Use Cases
---------

Use Case 1: Multi-Master Replication
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

By default, PGD Essential uses the PGD Connection Manager to send your
requests to the right node. This node is the write leader and by
directing your requests there, it allows conflicts to be rapidly
resolved.

With PGD Expanded, you can send your requests to any node in the
cluster, and PGD will replicate the changes to the other nodes.
Configurable conflict management then allows you to choose how to
resolve conflicts.

Use Case 2: Data Distribution
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

PGD Expanded allows you to distribute your data across multiple nodes in
the cluster, including subscriber-only read-only nodes. These nodes can
be located in multiple data centers or availability zones. This allows
you to scale your database’s read capacity horizontally, adding more
nodes to the cluster as needed.

Use Case 3: Geo-Distribution
^^^^^^^^^^^^^^^^^^^^^^^^^^^^

PGD Expanded allows you to distribute your data across multiple regions,
replicating data to all the nodes in the cluster. Multiple Data groups
can be located in different locations to ensure high availability and
resilience in that location.

Use Case 4: Tiered Tables
^^^^^^^^^^^^^^^^^^^^^^^^^

An optional element of PGD Expanded is the ability to create tiered
tables. These tables can be used to tier data between hot data, being
replicated within the cluster and cold data being written to a
Iceberg/Delta tables data lake. The cold data remains queryable as
Tiered Tables uses PGAA which allows you to query the data lake as if it
were a table in the database.