diff --git a/superset/migrations/versions/07071313dd52_change_fetch_values_predicate_to_text.py b/superset/migrations/versions/07071313dd52_change_fetch_values_predicate_to_text.py
index 320fb55a3524..ce90e37c8bd2 100644
--- a/superset/migrations/versions/07071313dd52_change_fetch_values_predicate_to_text.py
+++ b/superset/migrations/versions/07071313dd52_change_fetch_values_predicate_to_text.py
@@ -30,9 +30,7 @@
 
 import sqlalchemy as sa
 from alembic import op
-from sqlalchemy import and_, func, or_
-from sqlalchemy.dialects import postgresql
-from sqlalchemy.sql.schema import Table
+from sqlalchemy import func
 
 from superset import db
 from superset.connectors.sqla.models import SqlaTable
diff --git a/superset/migrations/versions/181091c0ef16_add_extra_column_to_columns_model.py b/superset/migrations/versions/181091c0ef16_add_extra_column_to_columns_model.py
index 6adeccf1c011..8ed0f0059817 100644
--- a/superset/migrations/versions/181091c0ef16_add_extra_column_to_columns_model.py
+++ b/superset/migrations/versions/181091c0ef16_add_extra_column_to_columns_model.py
@@ -28,9 +28,6 @@
 
 import sqlalchemy as sa
 from alembic import op
-from sqlalchemy.dialects import postgresql
-
-from superset.utils.core import generic_find_constraint_name
 
 
 def upgrade():
diff --git a/superset/migrations/versions/19e978e1b9c3_add_report_format_to_report_schedule_.py b/superset/migrations/versions/19e978e1b9c3_add_report_format_to_report_schedule_.py
index ab25b88c5e4d..ff191d0e3b29 100644
--- a/superset/migrations/versions/19e978e1b9c3_add_report_format_to_report_schedule_.py
+++ b/superset/migrations/versions/19e978e1b9c3_add_report_format_to_report_schedule_.py
@@ -28,7 +28,6 @@
 
 import sqlalchemy as sa
 from alembic import op
-from sqlalchemy.dialects import postgresql
 
 
 def upgrade():
diff --git a/superset/migrations/versions/3ba29ecbaac5_change_datatype_of_type_in_basecolumn.py b/superset/migrations/versions/3ba29ecbaac5_change_datatype_of_type_in_basecolumn.py
index 15f81488a310..4f94a4bb9bea 100644
--- a/superset/migrations/versions/3ba29ecbaac5_change_datatype_of_type_in_basecolumn.py
+++ b/superset/migrations/versions/3ba29ecbaac5_change_datatype_of_type_in_basecolumn.py
@@ -28,7 +28,6 @@
 
 import sqlalchemy as sa
 from alembic import op
-from sqlalchemy.dialects import postgresql
 
 
 def upgrade():
diff --git a/superset/migrations/versions/6d20ba9ecb33_add_last_saved_at_to_slice_model.py b/superset/migrations/versions/6d20ba9ecb33_add_last_saved_at_to_slice_model.py
index 408da5311841..c149adbc518d 100644
--- a/superset/migrations/versions/6d20ba9ecb33_add_last_saved_at_to_slice_model.py
+++ b/superset/migrations/versions/6d20ba9ecb33_add_last_saved_at_to_slice_model.py
@@ -28,7 +28,6 @@
 
 import sqlalchemy as sa
 from alembic import op
-from sqlalchemy.dialects import postgresql
 
 
 def upgrade():
diff --git a/superset/migrations/versions/73fd22e742ab_add_dynamic_plugins_py.py b/superset/migrations/versions/73fd22e742ab_add_dynamic_plugins_py.py
index e4c2d0bc519f..e2bbedcd347c 100644
--- a/superset/migrations/versions/73fd22e742ab_add_dynamic_plugins_py.py
+++ b/superset/migrations/versions/73fd22e742ab_add_dynamic_plugins_py.py
@@ -28,7 +28,6 @@
 
 import sqlalchemy as sa
 from alembic import op
-from sqlalchemy.dialects import postgresql
 
 
 def upgrade():