From b848e74164f2ff71c42f7183e8cd3c61b1dee479 Mon Sep 17 00:00:00 2001
From: axel_thevenot <axel_thevenot@ext.carrefour.com>
Date: Thu, 21 Nov 2024 19:12:01 +0100
Subject: [PATCH] refactor(incremental): optimize 'insert_overwrite' strategy
 (#1409)

---
 .../Under the Hood-20241121-191041.yaml       |  6 +++
 .../incremental_strategy/insert_overwrite.sql | 38 +++++++++++++++++++
 2 files changed, 44 insertions(+)
 create mode 100644 .changes/unreleased/Under the Hood-20241121-191041.yaml

diff --git a/.changes/unreleased/Under the Hood-20241121-191041.yaml b/.changes/unreleased/Under the Hood-20241121-191041.yaml
new file mode 100644
index 000000000..ce7526ef8
--- /dev/null
+++ b/.changes/unreleased/Under the Hood-20241121-191041.yaml	
@@ -0,0 +1,6 @@
+kind: Under the Hood
+body: 'refactor(incremental): optimize ''insert_overwrite'' strategy'
+time: 2024-11-21T19:10:41.341213+01:00
+custom:
+    Author: AxelThevenot
+    Issue: "1409"
diff --git a/dbt/include/bigquery/macros/materializations/incremental_strategy/insert_overwrite.sql b/dbt/include/bigquery/macros/materializations/incremental_strategy/insert_overwrite.sql
index 3ba67931e..9c69781db 100644
--- a/dbt/include/bigquery/macros/materializations/incremental_strategy/insert_overwrite.sql
+++ b/dbt/include/bigquery/macros/materializations/incremental_strategy/insert_overwrite.sql
@@ -1,3 +1,41 @@
+{% macro bigquery__get_insert_overwrite_merge_sql(target, source, dest_columns, predicates, include_sql_header) -%}
+    {#-- The only time include_sql_header is True: --#}
+    {#-- BigQuery + insert_overwrite strategy + "static" partitions config --#}
+    {#-- We should consider including the sql header at the materialization level instead --#}
+
+    {%- set predicates = [] if predicates is none else [] + predicates -%}
+    {%- set dest_cols_csv = get_quoted_csv(dest_columns | map(attribute="name")) -%}
+    {%- set sql_header = config.get('sql_header', none) -%}
+
+    {{ sql_header if sql_header is not none and include_sql_header }}
+
+    begin
+    begin transaction;
+
+        delete from {{ target }} as DBT_INTERNAL_DEST
+        where true
+        {%- if predicates %}
+            {% for predicate in predicates %}
+                and {{ predicate }}
+            {% endfor %}
+        {%- endif -%};
+
+        insert into {{ target }} ({{ dest_cols_csv }})
+        (
+            select {{ dest_cols_csv }}
+            from {{ source }}
+        );
+
+        commit transaction;
+
+    exception when error then
+        -- Roll if any error to avoid deleting rows.
+        raise using message = @@error.message;
+        rollback transaction;
+    end
+
+{% endmacro %}
+
 {% macro bq_generate_incremental_insert_overwrite_build_sql(
     tmp_relation, target_relation, sql, unique_key, partition_by, partitions, dest_columns, tmp_relation_exists, copy_partitions
 ) %}