diff --git a/initdb/02_3_2_signalk_public_functions.sql b/initdb/02_3_2_signalk_public_functions.sql
index c738f99..e58eff0 100644
--- a/initdb/02_3_2_signalk_public_functions.sql
+++ b/initdb/02_3_2_signalk_public_functions.sql
@@ -51,7 +51,7 @@ CREATE OR REPLACE FUNCTION logbook_update_avg_fn(
     OUT avg_speed double precision,
     OUT max_speed double precision,
     OUT max_wind_speed double precision,
-    OUT count_metric double precision
+    OUT count_metric integer
 ) AS $logbook_update_avg$
     BEGIN
         RAISE NOTICE '-> Updating avg for logbook id=%, start:"%", end:"%"', _id, _start, _end;
@@ -652,17 +652,6 @@ COMMENT ON FUNCTION
     public.get_app_settings_fn
     IS 'get app settings details, email, pushover, telegram';
 
-CREATE FUNCTION jsonb_key_exists(some_json jsonb, outer_key text)
-RETURNS BOOLEAN AS $$
-BEGIN
-    RETURN (some_json->outer_key) IS NOT NULL;
-END;
-$$ LANGUAGE plpgsql;
--- Description
-COMMENT ON FUNCTION
-    public.jsonb_key_exists
-    IS 'function that checks if an outer key exists in some_json and returns a boolean';
-
 -- Send notifications
 DROP FUNCTION IF EXISTS send_notification_fn;
 CREATE OR REPLACE FUNCTION send_notification_fn(
diff --git a/initdb/02_3_3_signalk_public_functions_helpers.sql b/initdb/02_3_3_signalk_public_functions_helpers.sql
new file mode 100644
index 0000000..3b6b39a
--- /dev/null
+++ b/initdb/02_3_3_signalk_public_functions_helpers.sql
@@ -0,0 +1,136 @@
+---------------------------------------------------------------------------
+-- singalk db public schema
+--
+
+-- List current database
+select current_database();
+
+-- connect to the DB
+\c signalk
+
+CREATE SCHEMA IF NOT EXISTS public;
+
+---------------------------------------------------------------------------
+-- basic helpers to check type and more
+--
+CREATE OR REPLACE FUNCTION public.isnumeric(text) RETURNS BOOLEAN AS
+$isnumeric$
+DECLARE x NUMERIC;
+BEGIN
+    x = $1::NUMERIC;
+    RETURN TRUE;
+EXCEPTION WHEN others THEN
+    RETURN FALSE;
+END;
+$isnumeric$
+STRICT
+LANGUAGE plpgsql IMMUTABLE;
+-- Description
+COMMENT ON FUNCTION
+    public.isnumeric
+    IS 'Check typeof value is numeric';
+
+CREATE OR REPLACE FUNCTION public.isboolean(text) RETURNS BOOLEAN AS
+$isboolean$
+DECLARE x BOOLEAN;
+BEGIN
+    x = $1::BOOLEAN;
+    RETURN TRUE;
+EXCEPTION WHEN others THEN
+    RETURN FALSE;
+END;
+$isboolean$
+STRICT
+LANGUAGE plpgsql IMMUTABLE;
+-- Description
+COMMENT ON FUNCTION
+    public.isboolean
+    IS 'Check typeof value is boolean';
+
+CREATE OR REPLACE FUNCTION public.isdate(s varchar) returns boolean as $$
+BEGIN
+  perform s::date;
+  return true;
+exception when others then
+  return false;
+END;
+$$ language plpgsql;
+-- Description
+COMMENT ON FUNCTION
+    public.isdate
+    IS 'Check typeof value is date';
+
+CREATE OR REPLACE FUNCTION public.istimestamptz(text) RETURNS BOOLEAN AS
+$isdate$
+DECLARE x TIMESTAMP WITHOUT TIME ZONE;
+BEGIN
+    x = $1::TIMESTAMP WITHOUT TIME ZONE;
+    RETURN TRUE;
+EXCEPTION WHEN others THEN
+    RETURN FALSE;
+END;
+$isdate$
+STRICT
+LANGUAGE plpgsql IMMUTABLE;
+-- Description
+COMMENT ON FUNCTION
+    public.istimestamptz
+    IS 'Check typeof value is TIMESTAMP WITHOUT TIME ZONE';
+
+---------------------------------------------------------------------------
+-- JSON helpers
+--
+CREATE FUNCTION jsonb_key_exists(some_json jsonb, outer_key text)
+RETURNS BOOLEAN AS $$
+BEGIN
+    RETURN (some_json->outer_key) IS NOT NULL;
+END;
+$$ LANGUAGE plpgsql;
+-- Description
+COMMENT ON FUNCTION
+    public.jsonb_key_exists
+    IS 'function that checks if an outer key exists in some_json and returns a boolean';
+
+-- https://stackoverflow.com/questions/42944888/merging-jsonb-values-in-postgresql
+CREATE OR REPLACE FUNCTION public.jsonb_recursive_merge(A jsonb, B jsonb)
+RETURNS jsonb LANGUAGE SQL AS $$
+    SELECT
+        jsonb_object_agg(
+            coalesce(ka, kb),
+            CASE
+            WHEN va isnull THEN vb
+            WHEN vb isnull THEN va
+            WHEN jsonb_typeof(va) <> 'object' OR jsonb_typeof(vb) <> 'object' THEN vb
+            ELSE jsonb_recursive_merge(va, vb) END
+        )
+        FROM jsonb_each(A) temptable1(ka, va)
+        FULL JOIN jsonb_each(B) temptable2(kb, vb) ON ka = kb
+$$;
+-- Description
+COMMENT ON FUNCTION
+    public.jsonb_recursive_merge
+    IS 'Merging JSONB values';
+
+-- https://stackoverflow.com/questions/36041784/postgresql-compare-two-jsonb-objects
+CREATE OR REPLACE FUNCTION public.jsonb_diff_val(val1 JSONB,val2 JSONB)
+RETURNS JSONB AS $jsonb_diff_val$
+    DECLARE
+    result JSONB;
+    v RECORD;
+    BEGIN
+    result = val1;
+    FOR v IN SELECT * FROM jsonb_each(val2) LOOP
+        IF result @> jsonb_build_object(v.key,v.value)
+            THEN result = result - v.key;
+        ELSIF result ? v.key THEN CONTINUE;
+        ELSE
+            result = result || jsonb_build_object(v.key,'null');
+        END IF;
+    END LOOP;
+    RETURN result;
+    END;
+$jsonb_diff_val$ LANGUAGE plpgsql;
+-- Description
+COMMENT ON FUNCTION
+    public.jsonb_diff_val
+    IS 'Compare two jsonb objects';