Add postgres - processlist and locks

postgresql.md

@@ -31,4 +31,34 @@ $ createdb -O <OWNER> <DBNAME>
 \c <DB>     connect to a database
 \dt         list tables
 \d <TABLE>  describe table
-```
+\df         list functions
+\dy         list trigger
+```
+
+## Find and kill query process
+
+To get a list of all currently running query process (like `SHOW FULL PROCESSLIST` from MySQL) enter:
+
+```sql
+SELECT * FROM pg_stat_activity;
+```
+
+If you know the name of the database you can filter with it like so:
+
+```sql
+SELECT * FROM pg_stat_activity WHERE datname= '<database name>';
+```
+
+With the entry of the `pid` column you can terminate or kill the process:
+
+```sql
+SELECT pg_cancel_backend(<pid>);  # Stop gracefully
+SELECT pg_terminate_backend(<pid>);  # Kill
+```
+
+## View locks
+
+```sql
+SELECT * FROM pg_locks;
+```
+