Merge branch 'postgres-index' into 'master'

Create index page for postgres

See merge request gitlab-org/gitlab!34851

doc/administration/high_availability/database.md

 ---
-type: reference
+redirect_to: '../postgresql/index.md'
 ---
 
-# Configuring PostgreSQL for Scaling and High Availability
-
-In this section, you'll be guided through configuring a PostgreSQL database to
-be used with GitLab in one of our [Scalable and Highly Available Setups](../reference_architectures/index.md).
-
-## Provide your own PostgreSQL instance **(CORE ONLY)**
-
-This content has been moved to a [new location](../postgresql/external.md).
-
-## Standalone PostgreSQL using Omnibus GitLab **(CORE ONLY)**
-
-This content has been moved to a [new location](../postgresql/standalone.md).
-
-## PostgreSQL replication and failover with Omnibus GitLab **(PREMIUM ONLY)**
-
-This content has been moved to a [new location](../postgresql/replication_and_failover.md).
+This document was moved to [another location](../postgresql/index.md).

doc/administration/postgresql/index.md

+---
+type: reference
+---
+
+# Configuring PostgreSQL for scaling
+
+In this section, you'll be guided through configuring a PostgreSQL database to
+be used with GitLab in one of our [Scalable and Highly Available Setups](../reference_architectures/index.md).
+There are essentially three setups to choose from.
+
+## PostgreSQL replication and failover with Omnibus GitLab **(PREMIUM ONLY)**
+
+This setup is for when you have installed GitLab using the
+[Omnibus GitLab **Enterprise Edition** (EE) package](https://about.gitlab.com/install/?version=ee).
+
+All the tools that are needed like PostgreSQL, PgBouncer, Repmgr are bundled in
+the package, so you can it to set up the whole PostgreSQL infrastructure (primary, replica).
+
+[> Read how to set up PostgreSQL replication and failover using Omnibus GitLab](replication_and_failover.md)
+
+## Standalone PostgreSQL using Omnibus GitLab **(CORE ONLY)**
+
+This setup is for when you have installed the
+[Omnibus GitLab packages](https://about.gitlab.com/install/) (CE or EE),
+to use the bundled PostgreSQL having only its service enabled.
+
+[> Read how to set up a standalone PostgreSQL instance using Omnibus GitLab](standalone.md)
+
+## Provide your own PostgreSQL instance **(CORE ONLY)**
+
+This setup is for when you have installed GitLab using the
+[Omnibus GitLab packages](https://about.gitlab.com/install/) (CE or EE),
+or installed it [from source](../../install/installation.md), but you want to use
+your own external PostgreSQL server.
+
+[> Read how to set up an external PostgreSQL instance](external.md)

doc/administration/postgresql/replication_and_failover.md

 # PostgreSQL replication and failover with Omnibus GitLab **(PREMIUM ONLY)**
 
-> Important notes:
->
-> - This document will focus only on configuration supported with [GitLab Premium](https://about.gitlab.com/pricing/), using the Omnibus GitLab package.
-> - If you are a Community Edition or Starter user, consider using a cloud hosted solution.
-> - This document will not cover installations from source.
->
-> - If a setup with replication and failover is not what you were looking for, see the [database configuration document](https://docs.gitlab.com/omnibus/settings/database.html)
->   for the Omnibus GitLab packages.
->
-> Please read this document fully before attempting to configure PostgreSQL with
-> replication and failover for GitLab.
+This document will focus only on configuration supported with [GitLab Premium](https://about.gitlab.com/pricing/), using the Omnibus GitLab package.
+If you are a Community Edition or Starter user, consider using a cloud hosted solution.
+This document will not cover installations from source.
+
+If a setup with replication and failover is not what you were looking for, see
+the [database configuration document](https://docs.gitlab.com/omnibus/settings/database.html)
+for the Omnibus GitLab packages.
+
+It's recommended to read this document fully before attempting to configure PostgreSQL with
+replication and failover for GitLab.
 
 ## Architecture