Add some notes about killing long running queries etc

notes/psql/long-running-queries.md

@@ -0,0 +1,38 @@
+---
+title: Find and kill long running queries
+tags:
+  - PostgreSQL
+link: https://medium.com/little-programming-joys/finding-and-killing-long-running-queries-on-postgres-7c4f0449e86d
+---
+
+# Running queries
+
+View a list of queries running longer than 5 minutes:
+
+```sql
+SELECT
+  pid,
+  now() - pg_stat_activity.query_start AS duration,
+  query,
+  state
+FROM pg_stat_activity
+WHERE (now() - pg_stat_activity.query_start) > interval '5 minutes';
+```
+
+Also see [running queries](../running-queries).
+
+# Stopping a given connection
+
+```sql
+SELECT pg_cancel_backend(pid);
+```
+
+`pid` being the relevant value from `pg_stat_activity.pid`.
+
+# Killing a given connection
+
+```sql
+SELECT pg_terminate_backend(pid);
+```
+
+Should be avoided, as it's synonymous with `kill -9`.

notes/psql/running-queries.md

@@ -0,0 +1,42 @@
+---
+title: Monitor running queries
+tags:
+  - PostgreSQL
+link: https://techmango.org/2017/11/04/monitor-running-queries-postgresql/
+---
+
+View a list of running queries:
+
+```sql
+SELECT
+  datname,
+  pid,
+  usename,
+  client_addr,
+  client_port,
+  xact_start,
+  backend_start,
+  query_start,
+  state,
+  query
+FROM pg_stat_activity
+ORDER BY query_start ASC
+```
+
+View list of non-idle connections:
+
+```sql
+SELECT
+  datname,
+  pid,
+  usename,
+  client_addr,
+  client_port,
+  xact_start,
+  backend_start,
+  query_start
+FROM pg_stat_activity
+WHERE
+  state != 'idle'
+ORDER BY query_start ASC
+```