Update cheatsheets

tldr/pg_upgrade

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+---
+syntax: markdown
+tags: [tldr, common]
+source: https://github.com/tldr-pages/tldr.git
+---
+# pg_upgrade
+
+> Upgrade a PostgreSQL database cluster to a new major version.
+> More information: <https://www.postgresql.org/docs/current/pgupgrade.html>.
+
+- Check clusters before upgrading:
+
+`pg_upgrade {{[-c|--check]}} {{[-b|--old-bindir]}} {{path/to/old_bin}} {{[-B|--new-bindir]}} {{path/to/new_bin}} {{[-d|--old-datadir]}} {{path/to/old_data}} {{[-D|--new-datadir]}} {{path/to/new_data}}`
+
+- Perform the actual upgrade:
+
+`pg_upgrade {{[-b|--old-bindir]}} {{path/to/old_bin}} {{[-B|--new-bindir]}} {{path/to/new_bin}} {{[-d|--old-datadir]}} {{path/to/old_data}} {{[-D|--new-datadir]}} {{path/to/new_data}}`
+
+- Use multiple parallel jobs during the upgrade:
+
+`pg_upgrade {{[-j|--jobs]}} {{njobs}} {{[-b|--old-bindir]}} {{path/to/old_bin}} {{[-B|--new-bindir]}} {{path/to/new_bin}} {{[-d|--old-datadir]}} {{path/to/old_data}} {{[-D|--new-datadir]}} {{path/to/new_data}}`
+
+- Specify the old and new PostgreSQL ports:
+
+`pg_upgrade {{[-p|--old-port]}} {{port}} {{[-P|--new-port]}} {{port}} {{[-b|--old-bindir]}} {{path/to/old_bin}} {{[-B|--new-bindir]}} {{path/to/new_bin}} {{[-d|--old-datadir]}} {{path/to/old_data}} {{[-D|--new-datadir]}} {{path/to/new_data}}`
+
+- Use hard links instead of copying files to the new cluster:
+
+`pg_upgrade {{[-k|--link]}} {{[-b|--old-bindir]}} {{path/to/old_bin}} {{[-B|--new-bindir]}} {{path/to/new_bin}} {{[-d|--old-datadir]}} {{path/to/old_data}} {{[-D|--new-datadir]}} {{path/to/new_data}}`
+
+- Display help:
+
+`pg_upgrade {{[-?|--help]}}`