File size: 9,198 Bytes
8da2481
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
defmodule Plausible.Stats.SQL.QueryBuilder do
  @moduledoc false

  use Plausible
  use Plausible.Stats.SQL.Fragments

  import Ecto.Query
  import Plausible.Stats.Imported
  import Plausible.Stats.Util

  alias Plausible.Stats.{Query, QueryOptimizer, TableDecider, SQL}
  alias Plausible.Stats.SQL.Expression
  alias Plausible.Stats.Legacy.TimeOnPage

  require Plausible.Stats.SQL.Expression

  def build(query, site) do
    query
    |> QueryOptimizer.split()
    |> Enum.map(fn {table_type, table_query} ->
      q = build_table_query(table_type, site, table_query)
      {table_type, table_query, q}
    end)
    |> join_query_results(query)
    |> build_order_by(query)
    |> paginate(query.pagination)
    |> select_total_rows(query.include.total_rows)
  end

  def build_order_by(q, query) do
    Enum.reduce(query.order_by || [], q, &build_order_by(&2, query, &1))
  end

  defp build_table_query(:events, site, events_query) do
    q =
      from(
        e in "events_v2",
        where: ^SQL.WhereBuilder.build(:events, events_query),
        where: ^SQL.WhereBuilder.derived_name_filter(events_query),
        select: ^select_event_metrics(events_query)
      )

    on_ee do
      q = Plausible.Stats.Sampling.add_query_hint(q, events_query)
    end

    q
    |> join_sessions_if_needed(events_query)
    |> build_group_by(:events, events_query)
    |> merge_imported(site, events_query)
    |> SQL.SpecialMetrics.add(site, events_query)
    |> TimeOnPage.merge_legacy_time_on_page(events_query)
  end

  defp build_table_query(:sessions, site, sessions_query) do
    q =
      from(
        e in "sessions_v2",
        where: ^SQL.WhereBuilder.build(:sessions, sessions_query),
        select: ^select_session_metrics(sessions_query)
      )

    on_ee do
      q = Plausible.Stats.Sampling.add_query_hint(q, sessions_query)
    end

    q
    |> join_events_if_needed(sessions_query)
    |> build_group_by(:sessions, sessions_query)
    |> merge_imported(site, sessions_query)
    |> SQL.SpecialMetrics.add(site, sessions_query)
  end

  defp join_sessions_if_needed(q, query) do
    if TableDecider.events_join_sessions?(query) do
      %{session: dimensions} = TableDecider.partition_dimensions(query)

      sessions_q =
        from(
          s in "sessions_v2",
          where: ^SQL.WhereBuilder.build(:sessions, query),
          where: s.sign == 1,
          select: %{session_id: s.session_id},
          group_by: s.session_id
        )

      # The session-only dimension columns are explicitly selected in joined
      # sessions table. This enables combining session-only dimensions (entry
      # and exit pages) with event-only metrics, like revenue.
      sessions_q =
        Enum.reduce(dimensions, sessions_q, fn dimension, acc ->
          Plausible.Stats.SQL.Expression.select_dimension_internal(acc, dimension)
        end)

      on_ee do
        sessions_q = Plausible.Stats.Sampling.add_query_hint(sessions_q, query)
      end

      from(
        e in q,
        join: sq in subquery(sessions_q),
        on: e.session_id == sq.session_id
      )
    else
      q
    end
  end

  def join_events_if_needed(q, query) do
    if TableDecider.sessions_join_events?(query) do
      events_q =
        from(e in "events_v2",
          where: ^SQL.WhereBuilder.build(:events, query),
          where: ^SQL.WhereBuilder.derived_name_filter(query),
          select: %{
            session_id: fragment("DISTINCT ?", e.session_id),
            _sample_factor: fragment("_sample_factor")
          }
        )

      on_ee do
        events_q = Plausible.Stats.Sampling.add_query_hint(events_q, query)
      end

      from(s in q,
        join: e in subquery(events_q),
        on: s.session_id == e.session_id
      )
    else
      q
    end
  end

  defp select_event_metrics(query) do
    query.metrics
    |> Enum.map(&SQL.Expression.event_metric(&1, query))
    |> Enum.reduce(%{}, &Map.merge/2)
  end

  defp select_session_metrics(query) do
    query.metrics
    |> Enum.map(&SQL.Expression.session_metric(&1, query))
    |> Enum.reduce(%{}, &Map.merge/2)
  end

  def build_group_by(q, :events, query) do
    # Session-only dimensions are extracted from joined sessions table
    %{session: session_only_dimensions} = TableDecider.partition_dimensions(query)
    event_dimensions = query.dimensions -- session_only_dimensions

    q =
      Enum.reduce(event_dimensions, q, &dimension_group_by(&2, :events, query, &1))

    Enum.reduce(
      session_only_dimensions,
      q,
      &dimension_group_by_join(&2, query, &1)
    )
  end

  def build_group_by(q, :sessions, query) do
    Enum.reduce(query.dimensions, q, &dimension_group_by(&2, :sessions, query, &1))
  end

  defp dimension_group_by_join(q, query, dimension) do
    key = shortname(query, dimension)

    q
    |> Expression.select_dimension_from_join(key, dimension)
    |> group_by([], selected_as(^key))
  end

  defp dimension_group_by(q, :events, query, "event:prop_key" = dimension) do
    from(e in q,
      join: meta in fragment("meta"),
      hints: "ARRAY",
      on: true,
      group_by: meta.key
    )
    |> select_merge_as([_e, meta], %{shortname(query, dimension) => meta.key})
  end

  defp dimension_group_by(q, :events, query, "event:goal" = dimension) do
    goal_join_data = Plausible.Stats.Goals.goal_join_data(query)

    if Enum.all?(goal_join_data.custom_props_keys, &Enum.empty?/1) do
      from(e in q,
        join: goal in Expression.event_goal_join_no_props(goal_join_data),
        hints: "ARRAY",
        on: true,
        select_merge: %{
          ^shortname(query, dimension) => fragment("?", goal)
        },
        group_by: goal
      )
    else
      from(e in q,
        join: goal in Expression.event_goal_join(goal_join_data),
        hints: "ARRAY",
        on: true,
        select_merge: %{
          ^shortname(query, dimension) => fragment("?", goal)
        },
        group_by: goal
      )
    end
  end

  defp dimension_group_by(q, table, query, dimension) do
    key = shortname(query, dimension)

    q
    |> Expression.select_dimension(key, dimension, table, query)
    |> group_by([], selected_as(^key))
  end

  defp build_order_by(q, query, {metric_or_dimension, order_direction}) do
    order_by(
      q,
      [t],
      {
        ^order_direction,
        selected_as(^shortname(query, metric_or_dimension))
      }
    )
  end

  # Only one table is being queried - skip joining!
  defp join_query_results([{_table_type, _query, q}], _main_query), do: q

  # Multiple tables: join results based on dimensions, select metrics from each and the appropriate dimensions.
  defp join_query_results(queries, main_query) do
    queries
    |> Enum.reduce(nil, fn
      {_table_type, query, q}, nil ->
        from(e in subquery(q))
        |> select_join_metrics(query, query.metrics)

      {_table_type, query, q}, acc ->
        join(acc, main_query.sql_join_type, [], s in subquery(q),
          on: ^build_group_by_join(main_query)
        )
        |> select_join_metrics(query, query.metrics -- [:sample_percent])
    end)
    |> select_dimensions(main_query, queries)
  end

  # NOTE: Old queries do their own pagination
  defp paginate(q, nil = _pagination), do: q

  defp paginate(q, pagination) do
    q
    |> limit(^pagination.limit)
    |> offset(^pagination.offset)
  end

  defp select_total_rows(q, false = _include_total_rows), do: q

  defp select_total_rows(q, true = _include_total_rows) do
    q
    |> select_merge([], %{total_rows: fragment("count() over ()")})
  end

  def build_group_by_join(%Query{dimensions: []}), do: true

  def build_group_by_join(query) do
    query.dimensions
    |> Enum.map(fn dim ->
      dynamic([a, ..., b], field(a, ^shortname(query, dim)) == field(b, ^shortname(query, dim)))
    end)
    |> Enum.reduce(fn condition, acc -> dynamic([], ^acc and ^condition) end)
  end

  defp select_join_metrics(q, query, metrics) do
    Enum.reduce(metrics, q, fn
      metric, q ->
        select_merge_as(q, [..., x], %{
          shortname(query, metric) => field(x, ^shortname(query, metric))
        })
    end)
  end

  defp select_dimensions(q, query, queries) do
    Enum.reduce(query.dimensions, q, fn dimension, q ->
      case select_from(dimension, query, queries) do
        :leftmost_table ->
          select_merge_as(q, [x], %{
            shortname(query, dimension) => field(x, ^shortname(query, dimension))
          })

        :rightmost_table ->
          select_merge_as(q, [..., x], %{
            shortname(query, dimension) => field(x, ^shortname(query, dimension))
          })
      end
    end)
  end

  defp select_from(dimension, query, queries) do
    smeared? = Enum.any?(queries, fn {_table_type, query, _q} -> query.smear_session_metrics end)

    cond do
      query.sql_join_type == :left -> :leftmost_table
      # We generally select dimensions from the left-most table. Only exception is time:minute/time:hour where
      # we use sessions table as smeared sessions are considered on-going during the whole period.
      dimension in ["time:minute", "time:hour"] and smeared? -> :rightmost_table
      true -> :leftmost_table
    end
  end
end