chore(postgres): slightly extend knowledge on tools

knowledge base/postgresql/pg_dump.md

@@ -3,7 +3,9 @@
 > [!caution]
 > TODO
 
-Intro
+Command-line tool for creating backups of a **single** PostgreSQL database.<br/>
+Consider using [`pg_dumpall`][pg_dumpall] to create backups of entire clusters, or global objects like roles and
+tablespaces.
 
 <!-- Remove this line to uncomment if used
 ## Table of contents <!-- omit in toc -->
@@ -14,6 +16,26 @@ Intro
 
 ## TL;DR
 
+It can dump a database in its entirety, or just specific parts of it such as individual tables or schemas.<br/>
+It does **not** dump objects like roles, groups, tablespace and others. Consider using [`pg_dumpall`][pg_dumpall] for
+those.
+
+It produces sets of SQL statements that can be executed to reproduce the original databases' object definitions and
+table data.
+
+Suitable when:
+
+- The database' size is **less** than 100 GB.<br/>
+  It tends to start giving issues for bigger databases.
+- One plans to migrate the database' metadata as well as the table data.
+- There is a relatively large number of tables to migrate.
+
+> [!important]
+> `pg_dump` works better when the database is taken offline, but it **does keep the database available** and will
+> **not** prevent users from accessing it.<br/>
+> Even with other users accessing the database during the backup process, `pg_dump` will **always** produce consistent
+> results thanks to ACID properties.
+
 <!-- Uncomment if used
 <details>
   <summary>Setup</summary>
@@ -54,6 +76,7 @@ Intro
 
 - [Documentation]
 - [A Complete Guide to pg_dump With Examples, Tips, and Tricks]
+- [How to speed up pg_dump when dumping large databases]
 
 <!--
   Reference
@@ -72,3 +95,4 @@ Intro
 
 <!-- Others -->
 [A Complete Guide to pg_dump With Examples, Tips, and Tricks]: https://www.dbvis.com/thetable/a-complete-guide-to-pg-dump-with-examples-tips-and-tricks/
+[How to speed up pg_dump when dumping large databases]: https://postgres.ai/docs/postgres-howtos/database-administration/backup-recovery/how-to-speed-up-pg-dump