chore(postgres): slightly extend knowledge on tools

knowledge base/postgresql/README.md

@@ -178,7 +178,8 @@ SELECT * FROM entries_in_column('vendors','vendor_id');
 
 ## Backup
 
-PostgreSQL offers the `pg_dump` and `pg_dumpall` native client utilities to dump databases to files.<br/>
+PostgreSQL offers the [`pg_dump`][pg_dump] and [`pg_dumpall`][pg_dumpall] native client utilities to dump databases to
+files.<br/>
 They produce sets of SQL statements that can be executed to reproduce the original databases' object definitions and
 table data.
 
@@ -241,6 +242,7 @@ pg_dumpall … -g --no-role-passwords
 > </details>
 
 A list of common backup tools can be found in the [PostgreSQL Wiki][wiki], in the [Backup][wiki backup] page.<br/>
+See also [dimitri/pgcopydb].<br/>
 For the _limited_™ experience accrued until now, the TL;DR is:
 
 - Prefer [pg_dumpall], and eventually [pg_dump], for **logical** backups.<br/>
@@ -357,6 +359,7 @@ See also [yugabyte/yugabyte-db].
 - [How to Scale a Single-Server Database: A Guide to Distributed PostgreSQL]
 - [yugabyte/yugabyte-db]
 - [Logical Decoding Concepts]
+- [dimitri/pgcopydb]
 
 ### Sources
 
@@ -403,6 +406,7 @@ See also [yugabyte/yugabyte-db].
 [the password file]: https://www.postgresql.org/docs/current/libpq-pgpass.html
 [wiki]: https://wiki.postgresql.org/wiki/
 [wiki backup]: https://wiki.postgresql.org/wiki/Ecosystem:Backup
+[dimitri/pgcopydb]: https://github.com/dimitri/pgcopydb
 
 <!-- Others -->
 [an in-depth guide to postgres data masking with anonymizer]: https://thelinuxcode.com/postgresql-anonymizer-data-masking/

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

knowledge base/postgresql/pg_dumpall.md

@@ -3,7 +3,9 @@
 > [!caution]
 > TODO
 
-Intro
+Command-line tool for creating backups of entire PostgreSQL clusters, and/or global objects like roles and
+tablespaces.<br/>
+Consider using [`pg_dump`][pg_dump] to create backups of a single database when nothing else is needed.
 
 <!-- Remove this line to uncomment if used
 ## Table of contents <!-- omit in toc -->
@@ -14,6 +16,25 @@ Intro
 
 ## TL;DR
 
+It can dump databases in their entirety, or just specific parts of them such as individual tables or schemas.<br/>
+It **can** dump objects like roles, groups, tablespace and others.
+
+It produces sets of SQL statements that can be executed to reproduce the original databases' object definitions and
+table data.
+
+Suitable when:
+
+- The databases' size is **less** than 100 GB.<br/>
+  It tends to start giving issues for bigger databases.
+- One plans to migrate the databases' metadata as well as the table data.
+- There is a relatively large number of tables to migrate.
+
+> [!important]
+> `pg_dumpall` 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_dumpall` will **always** produce
+> consistent results thanks to ACID properties.
+
 <!-- Uncomment if used
 <details>
   <summary>Setup</summary>

knowledge base/postgresql/pg_restore.md

@@ -53,6 +53,7 @@ Intro
 ### Sources
 
 - [Documentation]
+- [How to use pg_restore]
 
 <!--
   Reference
@@ -70,3 +71,4 @@ Intro
 [Documentation]: https://www.postgresql.org/docs/current/app-pgrestore.html
 
 <!-- Others -->
+[How to use pg_restore]: https://postgres.ai/docs/postgres-howtos/database-administration/backup-recovery/how-to-use-pg-restore