fix: add partial indexes on conversations for app_id with created_at/updated_at to resolve slow chat-conversations query

api/migrations/versions/2026_02_26_1336-e288952f2994_add_partial_indexes_on_conversations_.py

@@ -0,0 +1,37 @@
+"""add partial indexes on conversations for app_id with created_at and updated_at
+
+Revision ID: e288952f2994
+Revises: fce013ca180e
+Create Date: 2026-02-26 13:36:45.928922
+
+"""
+from alembic import op
+import sqlalchemy as sa
+
+# revision identifiers, used by Alembic.
+revision = 'e288952f2994'
+down_revision = 'fce013ca180e'
+branch_labels = None
+depends_on = None
+
+
+def upgrade():
+    with op.batch_alter_table('conversations', schema=None) as batch_op:
+        batch_op.create_index(
+            'conversation_app_created_at_idx',
+            ['app_id', sa.literal_column('created_at DESC')],
+            unique=False,
+            postgresql_where=sa.text('is_deleted IS false'),
+        )
+        batch_op.create_index(
+            'conversation_app_updated_at_idx',
+            ['app_id', sa.literal_column('updated_at DESC')],
+            unique=False,
+            postgresql_where=sa.text('is_deleted IS false'),
+        )
+
+
+def downgrade():
+    with op.batch_alter_table('conversations', schema=None) as batch_op:
+        batch_op.drop_index('conversation_app_updated_at_idx', postgresql_where=sa.text('is_deleted IS false'))
+        batch_op.drop_index('conversation_app_created_at_idx', postgresql_where=sa.text('is_deleted IS false'))

api/models/model.py

@@ -711,6 +711,18 @@ class Conversation(Base):
     __table_args__ = (
         sa.PrimaryKeyConstraint("id", name="conversation_pkey"),
         sa.Index("conversation_app_from_user_idx", "app_id", "from_source", "from_end_user_id"),
+        sa.Index(
+            "conversation_app_created_at_idx",
+            "app_id",
+            sa.text("created_at DESC"),
+            postgresql_where=sa.text("is_deleted IS false"),
+        ),
+        sa.Index(
+            "conversation_app_updated_at_idx",
+            "app_id",
+            sa.text("updated_at DESC"),
+            postgresql_where=sa.text("is_deleted IS false"),
+        ),
     )
 
     id: Mapped[str] = mapped_column(StringUUID, default=lambda: str(uuid4()))