Add support for pg_stat_statements configuration in Targets

This commit introduces a `use_pg_stat_statements` flag for targets, allowing users to enable or disable the use of `pg_stat_statements` for query insights. It includes database schema changes, backend logic, and UI updates to manage this setting in both creation and editing workflows.

backend/app/api/routes/targets.py

@@ -64,6 +64,7 @@ async def create_target(
         username=payload.username,
         encrypted_password=encrypt_secret(payload.password),
         sslmode=payload.sslmode,
+        use_pg_stat_statements=payload.use_pg_stat_statements,
         tags=payload.tags,
     )
     db.add(target)
@@ -188,6 +189,11 @@ async def get_activity(target_id: int, user: User = Depends(get_current_user), d
 @router.get("/{target_id}/top-queries", response_model=list[QueryStatOut])
 async def get_top_queries(target_id: int, user: User = Depends(get_current_user), db: AsyncSession = Depends(get_db)) -> list[QueryStatOut]:
     _ = user
+    target = await db.scalar(select(Target).where(Target.id == target_id))
+    if not target:
+        raise HTTPException(status_code=404, detail="Target not found")
+    if not target.use_pg_stat_statements:
+        return []
     rows = (
         await db.scalars(
             select(QueryStat)

backend/app/models/models.py

@@ -27,6 +27,7 @@ class Target(Base):
     username: Mapped[str] = mapped_column(String(120), nullable=False)
     encrypted_password: Mapped[str] = mapped_column(Text, nullable=False)
     sslmode: Mapped[str] = mapped_column(String(20), nullable=False, default="prefer")
+    use_pg_stat_statements: Mapped[bool] = mapped_column(Boolean, nullable=False, default=True)
     tags: Mapped[dict] = mapped_column(JSON, nullable=False, default=dict)
     created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), server_default=func.now(), nullable=False)
 

backend/app/schemas/target.py

@@ -9,6 +9,7 @@ class TargetBase(BaseModel):
     dbname: str
     username: str
     sslmode: str = "prefer"
+    use_pg_stat_statements: bool = True
     tags: dict = Field(default_factory=dict)
 
 
@@ -33,6 +34,7 @@ class TargetUpdate(BaseModel):
     username: str | None = None
     password: str | None = None
     sslmode: str | None = None
+    use_pg_stat_statements: bool | None = None
     tags: dict | None = None
 
 

backend/app/services/collector.py

@@ -106,18 +106,19 @@ async def collect_target(target: Target) -> None:
             cache_hit_ratio = stat_db["blks_hit"] / (stat_db["blks_hit"] + stat_db["blks_read"])
 
         query_rows = []
-        try:
-            query_rows = await conn.fetch(
-                """
-                SELECT queryid::text, calls, total_exec_time, mean_exec_time, rows, left(query, 2000) AS query_text
-                FROM pg_stat_statements
-                ORDER BY total_exec_time DESC
-                LIMIT 20
-                """
-            )
-        except Exception:
-            # Extension may be disabled on monitored instance.
-            query_rows = []
+        if target.use_pg_stat_statements:
+            try:
+                query_rows = await conn.fetch(
+                    """
+                    SELECT queryid::text, calls, total_exec_time, mean_exec_time, rows, left(query, 2000) AS query_text
+                    FROM pg_stat_statements
+                    ORDER BY total_exec_time DESC
+                    LIMIT 20
+                    """
+                )
+            except Exception:
+                # Extension may be disabled on monitored instance.
+                query_rows = []
 
         async with SessionLocal() as db:
             await _store_metric(db, target.id, "connections_total", activity["total_connections"], {})