Improve user in_guild sync query time by only loading the id column

This means the other, larger, columns do not need to be deserialised, bringing the query time down from 7.4s down to 3.5s.

I couldn't simply do select(models.User.id) here, as we need the full User object in order to mutate and update it later inthe process.

Author: ChrisLovering

metricity/exts/event_listeners/startup_sync.py

@@ -7,6 +7,7 @@
 from pydis_core.utils import logging, scheduling
 from sqlalchemy import column, select
 from sqlalchemy.dialects.postgresql import insert
+from sqlalchemy.orm import load_only
 
 from metricity import models
 from metricity.bot import Bot
@@ -95,7 +96,9 @@ async def sync_guild(self) -> None:
         users_updated = 0
         guild_member_ids = {str(member.id) for member in guild.members}
         async with async_session() as sess:
-            res = await sess.execute(select(models.User).filter_by(in_guild=True))
+
+            stmt = select(models.User).filter_by(in_guild=True).options(load_only(models.User.id))
+            res = await sess.execute(stmt)
             in_guild_users = res.scalars()
             for user in in_guild_users:
                 if user.id not in guild_member_ids: