Merge branch 'main' into fix/database-indexes-performance

Add indexes to ResearchHistory and ResearchTask models for frequently
queried columns to improve database query performance:

ResearchHistory:
- Add index on mode column (filtering by research mode)
- Add index on status column (filtering by status)
- Add index on created_at column (time-range queries)
- Add composite index on (status, created_at) for status listing
- Add composite index on (mode, status) for mode filtering

ResearchTask:
- Add index on status column (filtering by status)
- Add index on created_at column (time-range queries)
- Add composite index on (status, created_at) for task listing
- Add composite index on (priority, status) for priority-based queries

These indexes will significantly improve query performance for:
- History page listing
- Metrics dashboard aggregations
- Status filtering operations

src/local_deep_research/database/models/research.py

@@ -34,14 +34,14 @@ class ResearchTask(Base):
     title = Column(String(500), nullable=False)
     description = Column(Text)
     status = Column(
-        String(50), default="pending"
+        String(50), default="pending", index=True
     )  # pending, in_progress, completed, failed
     priority = Column(Integer, default=0)  # Higher number = higher priority
     tags = Column(JSON)  # List of tags for categorization
     research_metadata = Column(JSON)  # Flexible field for additional data
 
     # Timestamps
-    created_at = Column(UtcDateTime, default=utcnow())
+    created_at = Column(UtcDateTime, default=utcnow(), index=True)
     updated_at = Column(UtcDateTime, default=utcnow(), onupdate=utcnow())
     started_at = Column(UtcDateTime)
     completed_at = Column(UtcDateTime)
@@ -61,6 +61,12 @@ class ResearchTask(Base):
         "Report", back_populates="research_task", cascade="all, delete-orphan"
     )
 
+    # Indexes for performance on frequently queried columns
+    __table_args__ = (
+        Index("idx_research_task_status_created", "status", "created_at"),
+        Index("idx_research_task_priority_status", "priority", "status"),
+    )
+
     def __repr__(self):
         return f"<ResearchTask(title='{self.title}', status='{self.status}')>"
 
@@ -214,11 +220,11 @@ class ResearchHistory(Base):
     # The search query.
     query = Column(Text, nullable=False)
     # The mode of research (e.g., 'quick_summary', 'detailed_report').
-    mode = Column(Text, nullable=False)
+    mode = Column(Text, nullable=False, index=True)
     # Current status of the research.
-    status = Column(Text, nullable=False)
+    status = Column(Text, nullable=False, index=True)
     # The timestamp when the research started.
-    created_at = Column(Text, nullable=False)
+    created_at = Column(Text, nullable=False, index=True)
     # The timestamp when the research was completed.
     completed_at = Column(Text)
     # Duration of the research in seconds.
@@ -243,6 +249,12 @@ class ResearchHistory(Base):
         cascade="all, delete-orphan",
     )
 
+    # Indexes for performance on frequently queried columns
+    __table_args__ = (
+        Index("idx_research_history_status_created", "status", "created_at"),
+        Index("idx_research_history_mode_status", "mode", "status"),
+    )
+
     def __repr__(self):
         return f"<ResearchHistory(query='{self.query[:50]}...', status={self.status})>"
 

tests/database/test_database_indexes.py

@@ -0,0 +1,64 @@
+"""Tests for database index definitions on research models."""
+
+from local_deep_research.database.models.research import (
+    ResearchHistory,
+    ResearchTask,
+)
+
+
+class TestResearchTaskIndexes:
+    def test_status_column_indexed(self):
+        status_col = ResearchTask.__table__.columns["status"]
+        assert status_col.index is True
+
+    def test_created_at_column_indexed(self):
+        created_col = ResearchTask.__table__.columns["created_at"]
+        assert created_col.index is True
+
+    def test_composite_indexes_defined(self):
+        index_names = [idx.name for idx in ResearchTask.__table__.indexes]
+        assert "idx_research_task_status_created" in index_names
+        assert "idx_research_task_priority_status" in index_names
+
+    def test_composite_index_status_created_columns(self):
+        indexes = {idx.name: idx for idx in ResearchTask.__table__.indexes}
+        idx = indexes["idx_research_task_status_created"]
+        col_names = [col.name for col in idx.columns]
+        assert col_names == ["status", "created_at"]
+
+    def test_composite_index_priority_status_columns(self):
+        indexes = {idx.name: idx for idx in ResearchTask.__table__.indexes}
+        idx = indexes["idx_research_task_priority_status"]
+        col_names = [col.name for col in idx.columns]
+        assert col_names == ["priority", "status"]
+
+
+class TestResearchHistoryIndexes:
+    def test_status_column_indexed(self):
+        status_col = ResearchHistory.__table__.columns["status"]
+        assert status_col.index is True
+
+    def test_mode_column_indexed(self):
+        mode_col = ResearchHistory.__table__.columns["mode"]
+        assert mode_col.index is True
+
+    def test_created_at_column_indexed(self):
+        created_col = ResearchHistory.__table__.columns["created_at"]
+        assert created_col.index is True
+
+    def test_composite_indexes_defined(self):
+        index_names = [idx.name for idx in ResearchHistory.__table__.indexes]
+        assert "idx_research_history_status_created" in index_names
+        assert "idx_research_history_mode_status" in index_names
+
+    def test_composite_index_status_created_columns(self):
+        indexes = {idx.name: idx for idx in ResearchHistory.__table__.indexes}
+        idx = indexes["idx_research_history_status_created"]
+        col_names = [col.name for col in idx.columns]
+        assert col_names == ["status", "created_at"]
+
+    def test_composite_index_mode_status_columns(self):
+        indexes = {idx.name: idx for idx in ResearchHistory.__table__.indexes}
+        idx = indexes["idx_research_history_mode_status"]
+        col_names = [col.name for col in idx.columns]
+        assert col_names == ["mode", "status"]