Fix: Check if the target table exists when determining the value of the is_incremental flag

sqlmesh/core/snapshot/evaluator.py

@@ -773,7 +773,8 @@ def _evaluate_snapshot(
                         allow_destructive_snapshots=allow_destructive_snapshots,
                         allow_additive_snapshots=allow_additive_snapshots,
                     )
-                    common_render_kwargs["runtime_stage"] = RuntimeStage.EVALUATING
+                    runtime_stage = RuntimeStage.EVALUATING
+                    target_table_exists = True
                 elif model.annotated or model.is_seed or model.kind.is_scd_type_2:
                     self._execute_create(
                         snapshot=snapshot,
@@ -785,7 +786,14 @@ def _evaluate_snapshot(
                         dry_run=False,
                         run_pre_post_statements=False,
                     )
-                    common_render_kwargs["runtime_stage"] = RuntimeStage.EVALUATING
+                    runtime_stage = RuntimeStage.EVALUATING
+                    target_table_exists = True
+
+            evaluate_render_kwargs = {
+                **common_render_kwargs,
+                "runtime_stage": runtime_stage,
+                "snapshot_table_exists": target_table_exists,
+            }
 
             wap_id: t.Optional[str] = None
             if snapshot.is_materialized and (
@@ -801,7 +809,7 @@ def _evaluate_snapshot(
                 execution_time=execution_time,
                 snapshot=snapshot,
                 snapshots=snapshots,
-                render_kwargs=common_render_kwargs,
+                render_kwargs=evaluate_render_kwargs,
                 create_render_kwargs=create_render_kwargs,
                 rendered_physical_properties=rendered_physical_properties,
                 deployability_index=deployability_index,

sqlmesh/dbt/builtin.py

@@ -407,6 +407,12 @@ def create_builtin_globals(
             else snapshot.dev_intervals
         )
         is_incremental = bool(intervals)
+
+        snapshot_table_exists = jinja_globals.get("snapshot_table_exists")
+        if is_incremental and snapshot_table_exists is not None:
+            # If we know the information about table existence, we can use it to correctly
+            # set the flag
+            is_incremental &= snapshot_table_exists
     else:
         is_incremental = False
     builtin_globals["is_incremental"] = lambda: is_incremental

sqlmesh/dbt/seed.py

@@ -86,6 +86,7 @@ def to_sqlmesh(
             dialect=self.dialect(context),
             audit_definitions=audit_definitions,
             virtual_environment_mode=virtual_environment_mode,
+            start=self.start or context.sqlmesh_config.model_defaults.start,
             **kwargs,
         )
 

tests/core/test_integration.py

@@ -2037,6 +2037,35 @@ def test_dbt_select_star_is_directly_modified(sushi_test_dbt_context: Context):
     assert plan.snapshots[snapshot_b_id].change_category == SnapshotChangeCategory.NON_BREAKING
 
 
+@time_machine.travel("2023-01-08 15:00:00 UTC")
+def test_dbt_is_incremental_table_is_missing(sushi_test_dbt_context: Context):
+    context = sushi_test_dbt_context
+
+    model = context.get_model("sushi.waiter_revenue_by_day_v2")
+    model = model.copy(update={"kind": IncrementalUnmanagedKind(), "start": "2023-01-01"})
+    context.upsert_model(model)
+
+    context.plan("prod", auto_apply=True, no_prompts=True, skip_tests=True)
+
+    snapshot = context.get_snapshot("sushi.waiter_revenue_by_day_v2")
+    assert snapshot
+
+    # Manually drop the table
+    context.engine_adapter.drop_table(snapshot.table_name())
+
+    context.snapshot_evaluator.evaluate(
+        snapshot,
+        start="2023-01-01",
+        end="2023-01-08",
+        execution_time="2023-01-08 15:00:00",
+        snapshots={s.name: s for s in context.snapshots.values()},
+        deployability_index=DeployabilityIndex.all_deployable(),
+    )
+
+    # Make sure the table was recreated
+    assert context.engine_adapter.table_exists(snapshot.table_name())
+
+
 def test_model_attr(sushi_test_dbt_context: Context, assert_exp_eq):
     context = sushi_test_dbt_context
     model = context.get_model("sushi.top_waiters")

tests/dbt/test_config.py

@@ -354,7 +354,6 @@ def test_variables(assert_exp_eq, sushi_test_project):
 
     # Finally, check that variable scoping & overwriting (some_var) works as expected
     expected_sushi_variables = {
-        "start": "Jan 1 2022",
         "yet_another_var": 1,
         "top_waiters:limit": 10,
         "top_waiters:revenue": "revenue",
@@ -379,7 +378,6 @@ def test_variables(assert_exp_eq, sushi_test_project):
         "yet_another_var": 5,
         "customers:bla": False,
         "customers:customer_id": "customer_id",
-        "start": "Jan 1 2022",
     }
 
     assert sushi_test_project.packages["sushi"].variables == expected_sushi_variables
@@ -1006,8 +1004,11 @@ def test_db_type_to_quote_policy():
 def test_variable_override():
     project_root = "tests/fixtures/dbt/sushi_test"
     project = Project.load(
-        DbtContext(project_root=Path(project_root)),
-        variables={"yet_another_var": 2, "start": "2021-01-01"},
+        DbtContext(
+            project_root=Path(project_root),
+            sqlmesh_config=Config(model_defaults=ModelDefaultsConfig(start="2021-01-01")),
+        ),
+        variables={"yet_another_var": 2},
     )
     assert project.packages["sushi"].variables["yet_another_var"] == 2
 

tests/dbt/test_manifest.py

@@ -4,6 +4,7 @@
 
 import pytest
 
+from sqlmesh.core.config import ModelDefaultsConfig
 from sqlmesh.dbt.basemodel import Dependencies
 from sqlmesh.dbt.context import DbtContext
 from sqlmesh.dbt.manifest import ManifestHelper
@@ -24,7 +25,7 @@ def test_manifest_helper(caplog):
         project_path,
         "sushi",
         profile.target,
-        variable_overrides={"start": "2020-01-01"},
+        model_defaults=ModelDefaultsConfig(start="2020-01-01"),
     )
 
     models = helper.models()
@@ -135,7 +136,7 @@ def test_tests_referencing_disabled_models():
         project_path,
         "sushi",
         profile.target,
-        variable_overrides={"start": "2020-01-01"},
+        model_defaults=ModelDefaultsConfig(start="2020-01-01"),
     )
 
     assert "disabled_model" not in helper.models()
@@ -151,7 +152,7 @@ def test_call_cache():
         project_path,
         "sushi",
         profile.target,
-        variable_overrides={"start": "2020-01-01"},
+        model_defaults=ModelDefaultsConfig(start="2020-01-01"),
     )
 
     unused = "0000"
@@ -172,7 +173,7 @@ def test_variable_override():
         project_path,
         "sushi",
         profile.target,
-        variable_overrides={"start": "2020-01-01"},
+        model_defaults=ModelDefaultsConfig(start="2020-01-01"),
     )
     assert helper.models()["top_waiters"].limit_value == 10
 
@@ -181,7 +182,8 @@ def test_variable_override():
         project_path,
         "sushi",
         profile.target,
-        variable_overrides={"top_waiters:limit": 1, "start": "2020-01-01"},
+        variable_overrides={"top_waiters:limit": 1},
+        model_defaults=ModelDefaultsConfig(start="2020-01-01"),
     )
     assert helper.models()["top_waiters"].limit_value == 1
 
@@ -196,7 +198,7 @@ def test_source_meta_external_location():
         project_path,
         "sushi",
         profile.target,
-        variable_overrides={"start": "2020-01-01"},
+        model_defaults=ModelDefaultsConfig(start="2020-01-01"),
     )
 
     sources = helper.sources()
@@ -229,7 +231,7 @@ def test_top_level_dbt_adapter_macros():
         project_path,
         "sushi",
         profile.target,
-        variable_overrides={"start": "2020-01-01"},
+        model_defaults=ModelDefaultsConfig(start="2020-01-01"),
     )
 
     # Adapter macros must be marked as top-level

tests/dbt/test_transformation.py

@@ -1346,6 +1346,29 @@ def test_is_incremental(sushi_test_project: Project, assert_exp_eq, mocker):
         'SELECT 1 AS "one" FROM "tbl_a" AS "tbl_a" WHERE "ds" > (SELECT MAX("ds") FROM "model" AS "model")',
     )
 
+    # If the snapshot_table_exists flag was set to False, intervals should be ignored
+    assert_exp_eq(
+        model_config.to_sqlmesh(context)
+        .render_query_or_raise(snapshot=snapshot, snapshot_table_exists=False)
+        .sql(),
+        'SELECT 1 AS "one" FROM "tbl_a" AS "tbl_a"',
+    )
+
+    # If the snapshot_table_exists flag was set to True, intervals should be taken into account
+    assert_exp_eq(
+        model_config.to_sqlmesh(context)
+        .render_query_or_raise(snapshot=snapshot, snapshot_table_exists=True)
+        .sql(),
+        'SELECT 1 AS "one" FROM "tbl_a" AS "tbl_a" WHERE "ds" > (SELECT MAX("ds") FROM "model" AS "model")',
+    )
+    snapshot.intervals = []
+    assert_exp_eq(
+        model_config.to_sqlmesh(context)
+        .render_query_or_raise(snaspshot=snapshot, snapshot_table_exists=True)
+        .sql(),
+        'SELECT 1 AS "one" FROM "tbl_a" AS "tbl_a"',
+    )
+
 
 @pytest.mark.xdist_group("dbt_manifest")
 def test_is_incremental_non_incremental_model(sushi_test_project: Project, assert_exp_eq, mocker):

tests/fixtures/dbt/sushi_test/config.py

@@ -3,18 +3,17 @@
 from sqlmesh.core.config import ModelDefaultsConfig
 from sqlmesh.dbt.loader import sqlmesh_config
 
-variables = {"start": "Jan 1 2022"}
-
 
 config = sqlmesh_config(
-    Path(__file__).parent, variables=variables, model_defaults=ModelDefaultsConfig(dialect="duckdb")
+    Path(__file__).parent, model_defaults=ModelDefaultsConfig(dialect="duckdb", start="Jan 1 2022")
 )
 
 
 test_config = config
 
 test_config_with_normalization_strategy = sqlmesh_config(
     Path(__file__).parent,
-    variables=variables,
-    model_defaults=ModelDefaultsConfig(dialect="duckdb,normalization_strategy=LOWERCASE"),
+    model_defaults=ModelDefaultsConfig(
+        dialect="duckdb,normalization_strategy=LOWERCASE", start="Jan 1 2022"
+    ),
 )

tests/fixtures/dbt/sushi_test/dbt_project.yml

@@ -20,7 +20,6 @@ clean-targets:         # directories to be removed by `dbt clean`
 # Full documentation: https://docs.getdbt.com/docs/configuring-models
 
 models:
-  +start: "{{ var('start') }}"
   sushi:
     +materialized: table
     +pre-hook:

tests/fixtures/dbt/sushi_test/models/waiter_revenue_by_day.sql

@@ -30,11 +30,7 @@ LEFT JOIN {{ source('streaming', 'items') }} AS i
   ON oi.item_id = i.id AND oi.ds = i.ds
 {% if is_incremental() %}
   WHERE
-    o.ds > (select max(ds) from {{ this }})
-{% endif %}
-{% if sqlmesh_incremental is defined %}
-  WHERE
-      o.ds BETWEEN '{{ start_ds }}' AND '{{ end_ds }}'
+    o.ds > (select CAST(max(ds) AS DATE) from {{ this }})
 {% endif %}
 GROUP BY
   o.waiter_id,