chore: add first cookbook recipe.

use-timescale/cookbook.md

@@ -0,0 +1,75 @@
+---
+title: Timescale cookbook
+excerpt: Code examples from the community that help you with loads of common conundrums.   
+product: [cloud, mst, self_hosted] 
+---
+
+# Timescale cookbook
+
+This page contains suggestions from the [TimescaleDB Community](https://timescaledb.slack.com/)
+about how to resolve common issue. Use these code examples as guidance to work with your own data. 
+
+- [Remove duplicates from an existing hypertable](#remove-duplicates-from-an-existing-hypertable)
+
+## Remove duplicates from an existing hypertable
+
+Looking to remove duplicates from an existing hypertable? One method is to run a `PARTITION BY` query to get 
+`ROW_NUMBER()` and then the `ctid` of rows where `row_number>1`. You then delete these rows.  However,
+you need to check check `tableoid` and `ctid`. This is because `ctid` is not unique and might be duplicated in 
+different chunks. The following code example took 17 hours to process a table with 40 million rows:
+
+```sql
+CREATE OR REPLACE FUNCTION deduplicate_chunks(ht_name TEXT, partition_columns TEXT, bot_id INT DEFAULT NULL)
+    RETURNS TABLE
+            (
+                chunk_schema  name,
+                chunk_name    name,
+                deleted_count INT
+            )
+AS
+$$
+DECLARE
+    chunk         RECORD;
+    where_clause  TEXT := '';
+    deleted_count INT;
+BEGIN
+    IF bot_id IS NOT NULL THEN
+        where_clause := FORMAT('WHERE bot_id = %s', bot_id);
+    END IF;
+
+    FOR chunk IN
+        SELECT c.chunk_schema, c.chunk_name
+        FROM timescaledb_information.chunks c
+        WHERE c.hypertable_name = ht_name
+        LOOP
+            EXECUTE FORMAT('
+            WITH cte AS (
+                SELECT ctid,
+                       ROW_NUMBER() OVER (PARTITION BY %s ORDER BY %s ASC) AS row_num,
+                       *
+                FROM %I.%I
+                %s
+            )
+            DELETE FROM %I.%I
+            WHERE ctid IN (
+                SELECT ctid
+                FROM cte
+                WHERE row_num > 1
+            )
+            RETURNING 1;
+        ', partition_columns, partition_columns, chunk.chunk_schema, chunk.chunk_name, where_clause, chunk.chunk_schema,
+                           chunk.chunk_name)
+                INTO deleted_count;
+
+            RETURN QUERY SELECT chunk.chunk_schema, chunk.chunk_name, COALESCE(deleted_count, 0);
+        END LOOP;
+END
+$$ LANGUAGE plpgsql;
+
+
+SELECT *
+FROM deduplicate_chunks('nudge_events', 'bot_id, session_id, nudge_id, time', 2540);
+```
+
+ Shoutout to **Mathias Ose** and **Christopher Piggott** for this recipe. 
+

use-timescale/page-index/page-index.js

@@ -950,6 +950,11 @@ module.exports = [
           },
         ],
       },
+      {
+        title: "Timescale cookbook",
+        href: "cookbook",
+        excerpt: "Code examples from the community that help you with loads of common conundrums.",
+      },
       {
         title: "Timescale limitations",
         href: "limitations",