Integrating clickhouse for metrics.

lib/mixer/metrics/post_event.ex

@@ -0,0 +1,40 @@
+defmodule Mixer.Metrics.PostEvent do
+  @moduledoc """
+  Ecto schema that maps to the `post_events` table in ClickHouse.
+
+  Each row represents a single analytics event tied to a tweet (post).
+  The table uses a MergeTree engine ordered by `(occurred_at, event_type,
+  tweet_id)` for efficient time-range scans and per-tweet aggregations.
+
+  ## Event types
+
+  | event_type  | Description                              |
+  |-------------|------------------------------------------|
+  | `"view"`    | A tweet was displayed to a user          |
+  | `"like"`    | A user liked a tweet                     |
+  | `"unlike"`  | A user removed their like from a tweet   |
+  | `"comment"` | A user replied to a tweet                |
+  | `"share"`   | A user shared / reposted a tweet         |
+  """
+
+  use Ecto.Schema
+
+  @primary_key false
+
+  schema "post_events" do
+    # LowCardinality(String) in ClickHouse — keep values in the set above
+    field :event_type, :string
+
+    # The tweet that the event relates to
+    field :tweet_id, Ecto.UUID
+
+    # The acting user; may be nil for anonymous views
+    field :user_id, Ecto.UUID
+
+    # Wall-clock time of the event (UTC, second precision)
+    field :occurred_at, :utc_datetime
+
+    # Optional originating IP, useful for deduplicating anonymous views
+    field :ip_address, :string
+  end
+end