Align event_tags partition lifecycle with events

README.md

@@ -230,7 +230,7 @@ CSV env vars use comma-separated values. Boolean env vars accept `1/0`, `true/fa
 | Atom key | ENV | Default | Notes |
 | --- | --- | --- | --- |
 | `:check_interval_hours` | `PARRHESIA_RETENTION_CHECK_INTERVAL_HOURS` | `24` | Partition maintenance + pruning cadence |
-| `:months_ahead` | `PARRHESIA_RETENTION_MONTHS_AHEAD` | `2` | Pre-create current month plus N future monthly partitions |
+| `:months_ahead` | `PARRHESIA_RETENTION_MONTHS_AHEAD` | `2` | Pre-create current month plus N future monthly partitions for `events` and `event_tags` |
 | `:max_db_bytes` | `PARRHESIA_RETENTION_MAX_DB_BYTES` | `:infinity` | Interpreted as GiB threshold; accepts integer or `infinity` |
 | `:max_months_to_keep` | `PARRHESIA_RETENTION_MAX_MONTHS_TO_KEEP` | `:infinity` | Keep at most N months (including current month); accepts integer or `infinity` |
 | `:max_partitions_to_drop_per_run` | `PARRHESIA_RETENTION_MAX_PARTITIONS_TO_DROP_PER_RUN` | `1` | Safety cap for each maintenance run |

lib/parrhesia/storage/archiver.ex

@@ -9,6 +9,8 @@ defmodule Parrhesia.Storage.Archiver do
 
   @identifier_pattern ~r/^[a-zA-Z_][a-zA-Z0-9_]*$/
   @monthly_partition_pattern ~r/^events_(\d{4})_(\d{2})$/
+  @events_partition_prefix "events"
+  @event_tags_partition_prefix "event_tags"
   @default_months_ahead 2
 
   @type monthly_partition :: %{
@@ -74,7 +76,7 @@ defmodule Parrhesia.Storage.Archiver do
     Enum.reduce_while(offsets, :ok, fn offset, :ok ->
       target_month = shift_month(reference_month, offset)
 
-      case create_monthly_partition(target_month) do
+      case create_monthly_partitions(target_month) do
         :ok -> {:cont, :ok}
         {:error, reason} -> {:halt, {:error, reason}}
       end
@@ -95,18 +97,16 @@ defmodule Parrhesia.Storage.Archiver do
 
   @doc """
   Drops an event partition table by name.
+
+  For monthly `events_YYYY_MM` partitions, the matching `event_tags_YYYY_MM`
+  partition is dropped first to keep partition lifecycle aligned.
   """
   @spec drop_partition(String.t()) :: :ok | {:error, term()}
   def drop_partition(partition_name) when is_binary(partition_name) do
-    if partition_name in ["events", "events_default"] do
+    if protected_partition?(partition_name) do
       {:error, :protected_partition}
     else
-      quoted_partition_name = quote_identifier!(partition_name)
-
-      case Repo.query("DROP TABLE IF EXISTS #{quoted_partition_name}") do
-        {:ok, _result} -> :ok
-        {:error, reason} -> {:error, reason}
-      end
+      drop_partition_tables(partition_name)
     end
   end
 
@@ -122,23 +122,56 @@ defmodule Parrhesia.Storage.Archiver do
   end
 
   @doc """
-  Returns the monthly partition name for a date.
+  Returns the monthly `events` partition name for a date.
   """
   @spec month_partition_name(Date.t()) :: String.t()
   def month_partition_name(%Date{} = date) do
-    month = date.month |> Integer.to_string() |> String.pad_leading(2, "0")
-    "events_#{date.year}_#{month}"
+    monthly_partition_name(@events_partition_prefix, date)
   end
 
-  defp create_monthly_partition(%Date{} = month_date) do
-    partition_name = month_partition_name(month_date)
+  @doc """
+  Returns the monthly `event_tags` partition name for a date.
+  """
+  @spec event_tags_month_partition_name(Date.t()) :: String.t()
+  def event_tags_month_partition_name(%Date{} = date) do
+    monthly_partition_name(@event_tags_partition_prefix, date)
+  end
+
+  defp monthly_partition_name(prefix, %Date{} = date) do
+    month_suffix = date.month |> Integer.to_string() |> String.pad_leading(2, "0")
+    "#{prefix}_#{date.year}_#{month_suffix}"
+  end
+
+  defp create_monthly_partitions(%Date{} = month_date) do
     {start_unix, end_unix} = month_bounds_unix(month_date.year, month_date.month)
+
+    case create_monthly_partition(
+           month_partition_name(month_date),
+           @events_partition_prefix,
+           start_unix,
+           end_unix
+         ) do
+      :ok ->
+        create_monthly_partition(
+          event_tags_month_partition_name(month_date),
+          @event_tags_partition_prefix,
+          start_unix,
+          end_unix
+        )
+
+      {:error, reason} ->
+        {:error, reason}
+    end
+  end
+
+  defp create_monthly_partition(partition_name, parent_table_name, start_unix, end_unix) do
     quoted_partition_name = quote_identifier!(partition_name)
+    quoted_parent_table_name = quote_identifier!(parent_table_name)
 
     sql =
       """
       CREATE TABLE IF NOT EXISTS #{quoted_partition_name}
-      PARTITION OF "events"
+      PARTITION OF #{quoted_parent_table_name}
       FOR VALUES FROM (#{start_unix}) TO (#{end_unix})
       """
 
@@ -148,6 +181,76 @@ defmodule Parrhesia.Storage.Archiver do
     end
   end
 
+  defp drop_partition_tables(partition_name) do
+    case parse_monthly_partition(partition_name) do
+      nil -> drop_table(partition_name)
+      monthly_partition -> drop_monthly_partition(partition_name, monthly_partition)
+    end
+  end
+
+  defp drop_monthly_partition(partition_name, %{year: year, month: month}) do
+    month_date = Date.new!(year, month, 1)
+    tags_partition_name = monthly_partition_name(@event_tags_partition_prefix, month_date)
+
+    with :ok <- maybe_detach_events_partition(partition_name),
+         :ok <- drop_table(tags_partition_name) do
+      drop_table(partition_name)
+    end
+  end
+
+  defp maybe_detach_events_partition(partition_name) do
+    if attached_partition?(partition_name, @events_partition_prefix) do
+      quoted_parent_table_name = quote_identifier!(@events_partition_prefix)
+      quoted_partition_name = quote_identifier!(partition_name)
+
+      case Repo.query(
+             "ALTER TABLE #{quoted_parent_table_name} DETACH PARTITION #{quoted_partition_name}"
+           ) do
+        {:ok, _result} -> :ok
+        {:error, reason} -> {:error, reason}
+      end
+    else
+      :ok
+    end
+  end
+
+  defp attached_partition?(partition_name, parent_table_name) do
+    query =
+      """
+      SELECT 1
+      FROM pg_inherits AS inheritance
+      JOIN pg_class AS child ON child.oid = inheritance.inhrelid
+      JOIN pg_namespace AS child_ns ON child_ns.oid = child.relnamespace
+      JOIN pg_class AS parent ON parent.oid = inheritance.inhparent
+      JOIN pg_namespace AS parent_ns ON parent_ns.oid = parent.relnamespace
+      WHERE child_ns.nspname = 'public'
+        AND parent_ns.nspname = 'public'
+        AND child.relname = $1
+        AND parent.relname = $2
+      LIMIT 1
+      """
+
+    case Repo.query(query, [partition_name, parent_table_name]) do
+      {:ok, %{rows: [[1]]}} -> true
+      {:ok, %{rows: []}} -> false
+      {:ok, _result} -> false
+      {:error, _reason} -> false
+    end
+  end
+
+  defp drop_table(table_name) do
+    quoted_table_name = quote_identifier!(table_name)
+
+    case Repo.query("DROP TABLE IF EXISTS #{quoted_table_name}") do
+      {:ok, _result} -> :ok
+      {:error, reason} -> {:error, reason}
+    end
+  end
+
+  defp protected_partition?(partition_name) do
+    partition_name in ["events", "events_default", "event_tags", "event_tags_default"]
+  end
+
   defp parse_monthly_partition(partition_name) do
     case Regex.run(@monthly_partition_pattern, partition_name, capture: :all_but_first) do
       [year_text, month_text] ->

priv/repo/migrations/20260313192433_create_relay_storage.exs

@@ -30,7 +30,10 @@ defmodule Parrhesia.Repo.Migrations.CreateRelayStorage do
     create(index(:events, [:expires_at], where: "expires_at IS NOT NULL"))
     create(index(:events, [:deleted_at], where: "deleted_at IS NOT NULL"))
 
-    create table(:event_tags, primary_key: false) do
+    create table(:event_tags,
+             primary_key: false,
+             options: "PARTITION BY RANGE (event_created_at)"
+           ) do
       add(:event_created_at, :bigint, null: false)
       add(:event_id, :binary, null: false)
       add(:name, :string, null: false)
@@ -39,6 +42,8 @@ defmodule Parrhesia.Repo.Migrations.CreateRelayStorage do
       timestamps(updated_at: false, type: :utc_datetime_usec)
     end
 
+    execute("CREATE TABLE event_tags_default PARTITION OF event_tags DEFAULT")
+
     execute("""
     ALTER TABLE event_tags
     ADD CONSTRAINT event_tags_event_fk
@@ -149,6 +154,8 @@ defmodule Parrhesia.Repo.Migrations.CreateRelayStorage do
     drop(table(:banned_pubkeys))
     drop(table(:addressable_event_state))
     drop(table(:replaceable_event_state))
+
+    execute("DROP TABLE event_tags_default")
     drop(table(:event_tags))
 
     execute("DROP TABLE events_default")

test/parrhesia/storage/adapters/postgres/query_plan_regression_test.exs

@@ -64,7 +64,8 @@ defmodule Parrhesia.Storage.Adapters.Postgres.QueryPlanRegressionTest do
       )
 
     plan = Enum.map_join(explain.rows, "\n", &hd/1)
-    assert plan =~ "event_tags_h_value_created_at_idx"
+    assert plan =~ "Index Scan using event_tags_"
+    refute plan =~ "Filter: ((name)::text = 'h'::text)"
   end
 
   test "#i-heavy query plan uses dedicated event_tags i index" do
@@ -111,7 +112,8 @@ defmodule Parrhesia.Storage.Adapters.Postgres.QueryPlanRegressionTest do
       )
 
     plan = Enum.map_join(explain.rows, "\n", &hd/1)
-    assert plan =~ "event_tags_i_value_created_at_idx"
+    assert plan =~ "Index Scan using event_tags_"
+    refute plan =~ "Filter: ((name)::text = 'i'::text)"
   end
 
   defp persist_event(overrides) do

test/parrhesia/storage/archiver_test.exs

@@ -15,7 +15,7 @@ defmodule Parrhesia.Storage.ArchiverTest do
     assert is_list(partitions)
   end
 
-  test "ensure_monthly_partitions creates named monthly partitions" do
+  test "ensure_monthly_partitions creates aligned monthly partitions for events and event_tags" do
     assert :ok =
              Archiver.ensure_monthly_partitions(reference_date: ~D[2026-06-14], months_ahead: 1)
 
@@ -25,6 +25,9 @@ defmodule Parrhesia.Storage.ArchiverTest do
 
     assert "events_2026_06" in monthly_partition_names
     assert "events_2026_07" in monthly_partition_names
+
+    assert table_exists?("event_tags_2026_06")
+    assert table_exists?("event_tags_2026_07")
   end
 
   test "archive_sql builds insert-select statement" do
@@ -35,6 +38,21 @@ defmodule Parrhesia.Storage.ArchiverTest do
   test "drop_partition returns an error for protected partitions" do
     assert {:error, :protected_partition} = Archiver.drop_partition("events_default")
     assert {:error, :protected_partition} = Archiver.drop_partition("events")
+    assert {:error, :protected_partition} = Archiver.drop_partition("event_tags_default")
+    assert {:error, :protected_partition} = Archiver.drop_partition("event_tags")
+  end
+
+  test "drop_partition removes aligned event_tags partition for monthly event partition" do
+    assert :ok =
+             Archiver.ensure_monthly_partitions(reference_date: ~D[2026-08-14], months_ahead: 0)
+
+    assert table_exists?("events_2026_08")
+    assert table_exists?("event_tags_2026_08")
+
+    assert :ok = Archiver.drop_partition("events_2026_08")
+
+    refute table_exists?("events_2026_08")
+    refute table_exists?("event_tags_2026_08")
   end
 
   test "database_size_bytes returns the current database size" do
@@ -48,4 +66,12 @@ defmodule Parrhesia.Storage.ArchiverTest do
       Archiver.archive_sql("events_default; DROP TABLE events", "events_archive")
     end
   end
+
+  defp table_exists?(table_name) when is_binary(table_name) do
+    case Repo.query("SELECT to_regclass($1)", ["public." <> table_name]) do
+      {:ok, %{rows: [[nil]]}} -> false
+      {:ok, %{rows: [[_relation_name]]}} -> true
+      _other -> false
+    end
+  end
 end