Add an option to use INFORMATION_SCHEMA for partition info retrieval

.changes/unreleased/Features-20230807-235539.yaml

@@ -0,0 +1,6 @@
+kind: Features
+body: Add an option to use INFORMATION_SCHEMA for partition info retrieval
+time: 2023-08-07T23:55:39.31409+02:00
+custom:
+  Author: Kayrnt
+  Issue: "867"

dbt/adapters/bigquery/connections.py

@@ -598,15 +598,17 @@ def dry_run(self, sql: str) -> BigQueryAdapterResponse:
     def _bq_job_link(location, project_id, job_id) -> str:
         return f"https://console.cloud.google.com/bigquery?project={project_id}&j=bq:{location}:{job_id}&page=queryresults"
 
-    def get_partitions_metadata(self, table):
+    def get_partitions_metadata(self, table, use_legacy_sql=False):
         def standard_to_legacy(table):
             return table.project + ":" + table.dataset + "." + table.identifier
 
-        legacy_sql = "SELECT * FROM [" + standard_to_legacy(table) + "$__PARTITIONS_SUMMARY__]"
+        if use_legacy_sql:
+            sql = "SELECT * FROM [" + standard_to_legacy(table) + "$__PARTITIONS_SUMMARY__]"
+        else:
+            sql = f"SELECT * FROM `{table.project}.{table.dataset}.INFORMATION_SCHEMA.PARTITIONS` WHERE TABLE_NAME = '{table.identifier}'"
 
-        sql = self._add_query_comment(legacy_sql)
         # auto_begin is ignored on bigquery, and only included for consistency
-        _, iterator = self.raw_execute(sql, use_legacy_sql=True)
+        _, iterator = self.raw_execute(self._add_query_comment(sql), use_legacy_sql=use_legacy_sql)
         return self.get_table_from_response(iterator)
 
     def copy_bq_table(self, source, destination, write_disposition):

dbt/include/bigquery/macros/etc.sql

@@ -6,9 +6,17 @@
   {% do adapter.grant_access_to(entity, entity_type, role, grant_target_dict) %}
 {% endmacro %}
 
-{%- macro get_partitions_metadata(table) -%}
+{#
+  This macro returns the partition matadata for provided table.
+  The expected input is a table object (ie through a `source` or `ref`).
+  The output contains the result from partitions informations for your input table.
+  The details of the retrieved columns can be found on https://cloud.google.com/bigquery/docs/managing-partitioned-tables
+  if use_legacy_sql is set to True, the query will be executed using legacy sql and access the data from __PARTITIONS_SUMMARY__ meta-table
+  else it will leverage the INFORMATION_SCHEMA.PARTITIONS table.
+#}
+{%- macro get_partitions_metadata(table, use_legacy_sql = True) -%}
   {%- if execute -%}
-    {%- set res = adapter.get_partitions_metadata(table) -%}
+    {%- set res = adapter.get_partitions_metadata(table, use_legacy_sql) -%}
     {{- return(res) -}}
   {%- endif -%}
   {{- return(None) -}}

dbt/include/bigquery/macros/materializations/incremental_strategy/common.sql

@@ -2,12 +2,49 @@
 
   {#-- TODO: revisit partitioning with python models --#}
   {%- if '_dbt_max_partition' in compiled_code and language == 'sql' -%}
+    {%- if partition_by.partition_information = "information_schema" -%}
+      {{ dbt_max_partition_from_information_schema_data_sql(relation, partition_by) }}
+    {%- else -%}
+      {{ dbt_max_partition_from_table_data_sql(relation, partition_by) }}
+    {%- endif -%}
 
-    declare _dbt_max_partition {{ partition_by.data_type_for_partition() }} default (
+  {%- endif -%}
+
+{% endmacro %}
+
+{% macro dbt_max_partition_from_table_data_sql(relation, partition_by) %}
+
+  declare _dbt_max_partition {{ partition_by.data_type_for_partition() }} default (
       select max({{ partition_by.field }}) from {{ this }}
       where {{ partition_by.field }} is not null
-    );
+  );
 
+{% endmacro %}
+
+{% macro dbt_max_partition_from_information_schema_data_sql(relation, partition_by) %}
+
+  {%- if data_type is none -%}
+    {%- set data_type = partition_by.data_type -%}
+    {%- set granularity = partition_by.granularity -%}
   {%- endif -%}
 
+  {# Format partition_id to match the declared variable type #}
+    {%- if data_type | lower in ('date', 'timestamp', 'datetime') -%}
+        {%- if granularity = "day" -%}
+            {%- set format = "%Y%m%d" -%}
+        {%- else -%}
+            {%- set format = "%Y%m%d%H" -%}
+        {%- endif -%}
+        {%- set field = "parse_"  ~data_type ~ "('" ~ format ~ "', partition_id)" -%}
+    {%- else -%}
+        {%- set field = "CAST(partition_id AS INT64)" -%}
+  {%- endif -%}
+
+  declare _dbt_max_partition {{ partition_by.data_type_for_partition() }} default (
+      SELECT MAX({{ field }}) AS max_partition
+      FROM `{relation.project}.{relation.dataset}.INFORMATION_SCHEMA.PARTITIONS`
+      WHERE TABLE_NAME = '{relation.identifier}'
+      AND NOT(STARTS_WITH(partition_id, "__"))
+  );
+
 {% endmacro %}