feat: add doc/postgres-upgrade-pg_upgrade.md and doc/postgres-upgrade-pg_upgradecluster.md

doc/postgres-connect.md

@@ -1,28 +1,17 @@
 # Connect to Postgres Database Using Psql
 
-* configure Postgres like [this](./postgres.md)
-
-* create a database like [this](./postgres-create-db.md)
-
-* create a use like [this](./postgres-create-user.md)
-
-* when needed connect to Postgres as admin user locally
+* OPTION: connect to Postgres as admin user
 ```
-sudo -u postgres psql postgres -W
+sudo -u postgres psql -U postgres -W
 ```
 
-* when needed connect to the database <database name>
-as user <user name> locally
+* OPTION: connect to the database <database name> as user <user name>
 ```
 psql -U <user name> -d <database name> -W
 
 ```
 
-* when needed connect to the database <database name>
-as user <user name> to a remote Postgres instance at host
-<host name> and port <port number>\
-NOTE: Configure Postgres for remote connections like
-[this](./postgres.md)
+* OPTION: connect to the database <database name> as user <user name> to a remote Postgres instance at host <host name> and port <port number> (NOTE: Configure Postgres for remote connections like [this](./postgres.md))
 ```
 psql -h <host name> -p <port number> -U <user name> -d <database name> -W
 ```

doc/postgres-create-db.md

@@ -1,9 +1,9 @@
 # Create Database with Postgres
 
-* configure Postgres like [this](./postgres.md)
-
-* create a new database
+* create a new database <database name> and grant privileges to <user name>
 ```
 sudo -u postgres psql -W
 CREATE DATABASE <database name>;
+GRANT ALL PRIVILEGES ON DATABASE <database name> to <user name>;
+\q
 ```

doc/postgres-create-user.md

@@ -1,13 +1,12 @@
 # Create User with Postgres
 
-* configure Postgres like [this](./postgres.md)
-
-* create a database like [this](./postgres-create-db.md)
-
 * create a database user called <user name> with password <key>
 ```
-sudo -u postgres psql -W
 CREATE USER <user name> with encrypted password '<key>';
+```
+
+* OPTION: gant user <user_name> access to database <database name>
+```
 GRANT ALL PRIVILEGES ON DATABASE <database name> TO <user name>;
 ```
 
@@ -24,7 +23,7 @@ ALTER USER <user name> WITH ENCRYPTED PASSWORD '<key>';
 * OPTION: gant user <user_name> access to database ```postgres``` so that this user is able to login without providing a database
 ```
 sudo -u postgres psql -W
-grant all privileges on database postgres to <user name>;
+GRANT ALL PRIVILEGES ON DATABASE postgres to <user name>;
 ```
 
 * OPTION: gant user <user_name> permission to create databases

doc/postgres-upgrade-pg_upgrade.md

@@ -0,0 +1,65 @@
+# Upgrade using pg_upgrade
+
+* check clusters
+```
+pg_lsclusters
+```
+
+* do
+```
+sudo apt update
+sudo apt upgrade postgresql-xy
+```
+
+* install relevant packages
+```
+sudo apt-get install postgresql-server-dev-13
+```
+
+* make a backup
+```
+cd
+time sudo -u postgres pg_dumpall > bckp-all-2023-08-07
+```
+
+* check installed extensions on old version
+```
+sudo -u postgres psql -p 5432 postgres
+\dx
+```
+
+* install extension on new version
+```
+sudo apt install postgresql-13-postgis-3 --no-install-recommends
+sudo -u postgres psql -p 5433 postgres
+\dx
+CREATE EXTENSION postgis;
+CREATE EXTENSION hstore;
+```
+
+* stop all clusters
+```
+sudo systemctl stop postgresql
+systemctl status postgresql
+pg_lsclusters
+```
+
+* migrate
+```
+sudo -iu postgres /usr/lib/postgresql/13/bin/pg_upgrade \
+-o "-c config_file=/etc/postgresql/11/main/postgresql.conf" \
+--old-datadir=/var/lib/postgresql/11/main/ \
+-O "-c config_file=/etc/postgresql/13/main/postgresql.conf" \
+--new-datadir=/var/lib/postgresql/13/main/ \
+--old-bindir=/usr/lib/postgresql/11/bin \
+--new-bindir=/usr/lib/postgresql/13/bin --check --jobs=4
+```
+
+* TODO tbc
+
+* uninstall the previous version
+```
+sudo apt purge postgresql-11* postgresql-client- 11*
+sudo apt autoremove
+apt list --installed | grep postgresql-11 postgresql-client-11*
+```

doc/postgres-upgrade-pg_upgradecluster.md

@@ -0,0 +1,81 @@
+# Upgrade using pg_upgradecluster
+
+* check clusters
+```
+pg_lsclusters
+```
+
+* do
+```
+sudo apt update
+sudo apt upgrade postgresql-xy
+```
+
+* install relevant packages
+```
+sudo apt-get install postgresql-server-dev-13
+```
+
+* make a backup
+```
+cd
+time sudo -u postgres pg_dumpall > bckp-all-2023-08-07
+```
+
+* check installed extensions on old version
+```
+sudo -u postgres psql -p 5432 postgres
+\dx
+```
+
+* OPTION: install extension on new version
+```
+sudo apt install postgresql-13-postgis-3 --no-install-recommends
+sudo -u postgres psql -p 5433 postgres
+\dx
+CREATE EXTENSION postgis;
+CREATE EXTENSION hstore;
+```
+
+* stop all clusters
+```
+sudo systemctl stop postgresql
+systemctl status postgresql
+pg_lsclusters
+```
+
+* migrate
+```
+sudo systemctl stop postgresql@13-main
+sudo -u postgres pg_dropcluster 13 main
+sudo -u postgres pg_upgradecluster 11 main
+sudo systemctl daemon-reload
+systemctl status postgresql@13-main
+pg_lsclusters
+```
+
+* drop the old cluster:
+```
+sudo -u postgres pg_dropcluster 11 main
+```
+
+* uninstall the previous version
+```
+sudo apt purge postgresql-11* postgresql-client-11*
+sudo apt autoremove
+apt list --installed | grep postgresql-11 postgresql-client-11*
+```
+
+* do
+```
+sudo pg_ctlcluster 13 main stop
+pg_lsclusters
+sudo pg_ctlcluster 13 main start
+pg_lsclusters
+```
+
+* vacuum
+```
+sudo -u postgres vacuumdb --all --analyze-only
+sudo -u postgres vacuumdb --all
+```