Install PostgreSQL DB and document DB usage

docs/AI-Usage.md

@@ -5,6 +5,7 @@ AI is prone to halucinations and mistakes, therefore will AI used in a thoughtfu
 ## Tools used
 Different group members use different harnesses and models, according to personal preference.
 * Mistral Vibe Code CLI
+* Mistral Vibe Work
 
 ## Summary of how AI was used
 ...
@@ -14,4 +15,6 @@ Different group members use different harnesses and models, according to persona
 | --- | --- | ---- | ------------ |
 | 29.09.2026 | Daniel | Mistral Vibe Work, Mistral Vibe Code CLI  | Critize my PRD in context of best practices and project description |
 | 29.09.2026 | Daniel | Mistral Vibe Work | Find fitting labels for issues and PRs for the project |
+| 9.10.2026 | Daniel | Mistral Vibe Work | Help with freeing disk space on VM and make a list over usefull postgreSQL command |
+
 

docs/postgresql-management.md

@@ -0,0 +1,27 @@
+# Manage Postgresql database
+SSH into the VM to manage the database. There is currntly no exposed postgreSQL ports for remote management other than trough SSH.
+
+## Connect to the database and run queries.
+Run as the postgres system user. Use your user account password if sudo requests it.
+```
+sudo -u postgres psql
+```
+
+Run a sinlge query
+```
+sudo -u postgres psql -c "SELECT example FROM EXAMPLE;"
+```
+
+## Some handful commands inside psql — meta-commands
+| Command | What it does |
+| --- | --- |
+| `\l` | List all databases |
+| `\c mydb` | Switch to another database |
+| `\dt` | List tables in the current schema |
+| `\d mytable` | Describe a table (columns, types, indexes) |
+| `\du` | List roles/users and their privileges |
+| `\dn` | List schemas |
+| `\x` | Toggle expanded row display (great for wide rows) |
+| `\timing` | Show how long each query takes |
+| `\i script.sql` | Execute a SQL file |
+| `\q` | Quit |

docs/postgresql-setup.md

@@ -0,0 +1,55 @@
+# PostgreSQL setup/install
+
+## VM needed cleanup
+The VM was full, no avialable storage. The install failed first time.
+Before:
+```
+$ df -h /
+Filesystem                         Size  Used Avail Use% Mounted on
+/dev/mapper/ubuntu--vg-ubuntu--lv   22G   21G     0 100% /
+```
+
+Commands i used to get back some storage space.
+```
+sudo apt-get clean
+sudo journalctl --vacuum-size=100M
+sudo apt-get autoremove --purge && sudo apt-get autoclean
+```
+
+After:
+```
+Filesystem                         Size  Used Avail Use% Mounted on
+/dev/mapper/ubuntu--vg-ubuntu--lv   22G   19G  2.0G  91% /
+```
+
+## Installing PostgreSQL
+```
+apt install postgresql
+```
+
+Check that it is running
+```
+$ systemctl status postgresql
+● postgresql.service - PostgreSQL RDBMS
+     Loaded: loaded (/usr/lib/systemd/system/postgresql.service; enabled; preset: enabled)
+     Active: active (exited) since Fri 2026-10-09 10:45:03 CEST; 1min 2s ago
+ Invocation: 53a72781a00d4fe89442166a499e2145
+   Main PID: 1823221 (code=exited, status=0/SUCCESS)
+   Mem peak: 1.7M
+        CPU: 4ms
+```
+```
+$ pg_isready
+/var/run/postgresql:5432 - accepting connections
+$ sudo ss -ltnp | grep 5432
+LISTEN 0      200        127.0.0.1:5432      0.0.0.0:*    users:(("postgres",pid=1824131,fd=6))                                                       
+$ sudo -u postgres psql
+psql (18.6 (Ubuntu 18.6-0ubuntu0.26.04.1))
+Type "help" for help.
+
+postgres=# SELECT version();
+                                                             version                                                             
+---------------------------------------------------------------------------------------------------------------------------------
+ PostgreSQL 18.6 (Ubuntu 18.6-0ubuntu0.26.04.1) on x86_64-pc-linux-gnu, compiled by gcc (Ubuntu 15.2.0-16ubuntu1) 15.2.0, 64-bit
+```
+