RHIDP-8629: sizing requirements for external PostgreSQL deployment with RHDH

modules/about/ref-rhdh-sizing.adoc

@@ -3,7 +3,10 @@
 [id="rhdh-sizing_{context}"]
 = Sizing requirements for {product}
 
-Scaling the {product} requires significant resource allocation. The following table lists the sizing requirements for installing and running {product}, including {product-short} application, database components, and Operator.
+Learn about sizing requirements for {product}.
+Table 1 lists the sizing requirements for installing and running {product},
+including {product-short} application, database components, and Operator.
+Table 2 lists recommended sizing requirements for xref:configuring-external-postgresql-databases[external PostgreSQL deployment] based on the deployment scale.
 
 .Recommended sizing for running {product}
 [cols="25%,25%,25%,25%", frame="all", options="header"]
@@ -33,3 +36,53 @@ Scaling the {product} requires significant resource allocation. The following ta
 |3 or more
 |1 or more
 |===
+
+.Recommended sizing for external PostgreSQL deployments with {product}
+[cols="25%,25%,25%,25%,25%" frame="all", options="header"]
+|===
+
+|Sizing legend
+|Small-scale
+|Mid-scale
+|Large-scale
+|Enterprise-scale
+
+|Application usage
+|up to 5 thousand entities, up to 50 concurrent users
+|5–20 thousand entities, 501–50 concurrent users
+|20–50 thousand entities, 150–400 concurrent users
+|50–150 thousand entities, 400–800 concurrent users
+
+|vCPU
+|2
+|4
+|8
+|16
+
+|Memory
+|8 GiB
+|16 GiB
+|32 GiB
+|64 GiB
+
+|Storage
+|50 GiB
+|100 GiB
+|200 GiB
+|500 GiB
+
+|Number of replicas
+|1
+|2
+|2-3
+|3+
+
+|PostgreSQL Database HA
+|1 primary
+|1 primary, 1 standby
+|1 primary, 1 synchronous standby
+|1 primary, 1 synchronous standby, 1 asynchronous replica
+
+
+
+

modules/configuring-external-databases/proc-configuring-postgresql-instance-using-helm.adoc

@@ -7,6 +7,7 @@ You can configure an external PostgreSQL instance by using the Helm Chart. By de
 
 .Prerequisites
 
+* You meet the sizing requirements listed in Table 4.2 Recommended sizing for external PostgreSQL deployments with {product} in xref:rhdh-sizing_{context}[Sizing requirements for {product}]
 * You are using a supported version of PostgreSQL. For more information, see the link:https://access.redhat.com/support/policy/updates/developerhub[Product life cycle page].
 * You have the following details:
 ** `db-host`: Denotes your PostgreSQL instance Domain Name System (DNS) or IP address

modules/configuring-external-databases/proc-configuring-postgresql-instance-using-the-operator.adoc

@@ -7,6 +7,7 @@ You can configure an external PostgreSQL instance using the {product} Operator.
 
 .Prerequisites
 
+* You meet the sizing requirements listed in Table 4.2 Recommended sizing for external PostgreSQL deployments with {product} in xref:rhdh-sizing_{context}[Sizing requirements for {product}]
 * You are using a supported version of PostgreSQL. For more information, see the link:https://access.redhat.com/support/policy/updates/developerhub[Product life cycle page].
 * You have the following details:
 ** `db-host`: Denotes your PostgreSQL instance Domain Name System (DNS) or IP address