insert_by_period_materialization.sql

{% macro get_period_boundaries(target_schema, target_table, timestamp_field, start_date, stop_date, period) -%}

  {% call statement('period_boundaries', fetch_result=True) -%}
    with data as (
      select
          coalesce(max("{{timestamp_field}}"), '{{start_date}}')::timestamp as start_timestamp,
          coalesce(
            {{dbt_utils.dateadd('millisecond',
                                -1,
                                "nullif('" ~ stop_date ~ "','')::timestamp")}},
            {{dbt_utils.current_timestamp()}}
          ) as stop_timestamp
      from "{{target_schema}}"."{{target_table}}"
    )

    select
      start_timestamp,
      stop_timestamp,
      {{dbt_utils.datediff('start_timestamp',
                           'stop_timestamp',
                           period)}}  + 1 as num_periods
    from data
  {%- endcall %}

{%- endmacro %}

{% macro get_period_sql(target_cols_csv, sql, timestamp_field, period, start_timestamp, stop_timestamp, offset) -%}

  {%- set period_filter -%}
    ("{{timestamp_field}}" >  '{{start_timestamp}}'::timestamp + interval '{{offset}} {{period}}' and
     "{{timestamp_field}}" <= '{{start_timestamp}}'::timestamp + interval '{{offset}} {{period}}' + interval '1 {{period}}' and
     "{{timestamp_field}}" <  '{{stop_timestamp}}'::timestamp)
  {%- endset -%}

  {%- set filtered_sql = sql | replace("__PERIOD_FILTER__", period_filter) -%}

  select
    {{target_cols_csv}}
  from (
    {{filtered_sql}}
  )

{%- endmacro %}

{% materialization insert_by_period, default -%}
  {%- set timestamp_field = config.require('timestamp_field') -%}
  {%- set start_date = config.require('start_date') -%}
  {%- set stop_date = config.get('stop_date') or '' -%}}
  {%- set period = config.get('period') or 'week' -%}

  {%- if sql.find('__PERIOD_FILTER__') == -1 -%}
    {%- set error_message -%}
      Model '{{ model.unique_id }}' does not include the required string '__PERIOD_FILTER__' in its sql
    {%- endset -%}
    {{ exceptions.raise_compiler_error(error_message) }}
  {%- endif -%}

  {%- set identifier = model['name'] -%}

  {%- set old_relation = adapter.get_relation(database=database, schema=schema, identifier=identifier) -%}
  {%- set target_relation = api.Relation.create(identifier=identifier, schema=schema, type='table') -%}

  {%- set non_destructive_mode = (flags.NON_DESTRUCTIVE == True) -%}
  {%- set full_refresh_mode = (flags.FULL_REFRESH == True) -%}

  {%- set exists_as_table = (old_relation is not none and old_relation.is_table) -%}
  {%- set exists_not_as_table = (old_relation is not none and not old_relation.is_table) -%}

  {%- set should_truncate = (non_destructive_mode and full_refresh_mode and exists_as_table) -%}
  {%- set should_drop = (not should_truncate and (full_refresh_mode or exists_not_as_table)) -%}
  {%- set force_create = (flags.FULL_REFRESH and not flags.NON_DESTRUCTIVE) -%}

  -- setup
  {% if old_relation is none -%}
    -- noop
  {%- elif should_truncate -%}
    {{adapter.truncate_relation(old_relation)}}
  {%- elif should_drop -%}
    {{adapter.drop_relation(old_relation)}}
    {%- set old_relation = none -%}
  {%- endif %}

  {{run_hooks(pre_hooks, inside_transaction=False)}}

  -- `begin` happens here, so `commit` after it to finish the transaction
  {{run_hooks(pre_hooks, inside_transaction=True)}}
  {% call statement() -%}
    begin; -- make extra sure we've closed out the transaction
    commit;
  {%- endcall %}

  -- build model
  {% if force_create or old_relation is none -%}
    {# Create an empty target table -#}
    {% call statement('main') -%}
      {%- set empty_sql = sql | replace("__PERIOD_FILTER__", 'false') -%}
      {{create_table_as(False, target_relation, empty_sql)}};
    {%- endcall %}
  {%- endif %}

  {% set _ = dbt_utils.get_period_boundaries(schema,
                                              identifier,
                                              timestamp_field,
                                              start_date,
                                              stop_date,
                                              period) %}
  {%- set start_timestamp = load_result('period_boundaries')['data'][0][0] | string -%}
  {%- set stop_timestamp = load_result('period_boundaries')['data'][0][1] | string -%}
  {%- set num_periods = load_result('period_boundaries')['data'][0][2] | int -%}

  {% set target_columns = adapter.get_columns_in_relation(target_relation) %}
  {%- set target_cols_csv = target_columns | map(attribute='quoted') | join(', ') -%}
  {%- set loop_vars = {'sum_rows_inserted': 0} -%}

  -- commit each period as a separate transaction
  {% for i in range(num_periods) -%}
    {%- set msg = "Running for " ~ period ~ " " ~ (i + 1) ~ " of " ~ (num_periods) -%}
    {{ dbt_utils.log_info(msg) }}

    {%- set tmp_identifier = model['name'] ~ '__dbt_incremental_period' ~ i ~ '_tmp' -%}
    {%- set tmp_relation = api.Relation.create(identifier=tmp_identifier,
                                               schema=schema, type='table') -%}
    {% call statement() -%}
      {% set tmp_table_sql = dbt_utils.get_period_sql(target_cols_csv,
                                                       sql,
                                                       timestamp_field,
                                                       period,
                                                       start_timestamp,
                                                       stop_timestamp,
                                                       i) %}
      {{dbt.create_table_as(True, tmp_relation, tmp_table_sql)}}
    {%- endcall %}

    {{adapter.expand_target_column_types(from_relation=tmp_relation,
                                         to_relation=target_relation)}}
    {%- set name = 'main-' ~ i -%}
    {% call statement(name, fetch_result=True) -%}
      insert into {{target_relation}} ({{target_cols_csv}})
      (
          select
              {{target_cols_csv}}
          from {{tmp_relation.include(schema=False)}}
      );
    {%- endcall %}
    {%- set rows_inserted = (load_result('main-' ~ i)['status'].split(" "))[2] | int -%}
    {%- set sum_rows_inserted = loop_vars['sum_rows_inserted'] + rows_inserted -%}
    {%- if loop_vars.update({'sum_rows_inserted': sum_rows_inserted}) %} {% endif -%}

    {%- set msg = "Ran for " ~ period ~ " " ~ (i + 1) ~ " of " ~ (num_periods) ~ "; " ~ rows_inserted ~ " records inserted" -%}
    {{ dbt_utils.log_info(msg) }}

  {%- endfor %}

  {% call statement() -%}
    begin;
  {%- endcall %}

  {{run_hooks(post_hooks, inside_transaction=True)}}

  {% call statement() -%}
    commit;
  {%- endcall %}

  {{run_hooks(post_hooks, inside_transaction=False)}}

  {%- set status_string = "INSERT " ~ loop_vars['sum_rows_inserted'] -%}

  {% call noop_statement(name='main', status=status_string) -%}
    -- no-op
  {%- endcall %}

  -- Return the relations created in this materialization
  {{ return({'relations': [target_relation]}) }}  

{%- endmaterialization %}