Firestore delete vs update time and performance

问题

I have coded a match making system and this system works like that --> when a create operation came to firestore it matches with an older record and the cloud function deletes both of them. But i wonder that when 2 new records are created, is there any chance for matching these 2 with the same old record because the deletion process takes some time?

Also, if i do that process with update, is it faster than delete?

EDIT:

Here is my matchMaker Cloud Function:

exports.matchMaker = functions.firestore
  .document("WaitingRooms/{gameId}/Users/{matchId}")
  .onCreate(async (snap, context) => {
    const data = snap.data();
    const gameId = context.params.gameId;
    const data2 = await db.collection("Users").doc(data["userId"]).get();
    const data3 = await db
      .collection("WaitingRooms")
      .doc(gameId)
      .collection("Users")
      .where("userId", "!=", data["userId"])
      .limit(1)
      .get();

      if(data3.docs[0])
      {
      let match = data3.docs[0].data()["userId"]
      matchPN = await db.collection("Users").doc(match).get();
      matchPushNotifications = matchPN.data()["pushNotificationsTokens"];
      myPushNotifications = data2.data()["pushNotificationsTokens"];
      await db
        .collection("Users")
        .doc(match)
        .update({
          waitingMatches: admin.firestore.FieldValue.arrayUnion({id:data["userId"]}),
        });
      await db
        .collection("Users")
        .doc(data["userId"])
        .update({
          waitingMatches: admin.firestore.FieldValue.arrayUnion({id:match}),
        });

     //SOME OTHER CODES
      
      await db
        .collection("WaitingRooms")
        .doc(gameId)
        .collection("Users")
        .doc(data3.docs[0].id)
        .delete();
      await db
      .collection("WaitingRooms")
      .doc(gameId)
      .collection("Users")
      .doc(context.params.matchId)
      .delete();
  }
    

  });

This code work correctly but the problem is that if Waiting Rooms/{gameId}/Users/ has three records, the code matches 3 of them but i want to match 2 of them and one of them has to remain.

I know cloud function can not know which one is matched or not but how can i check that?

来源：https://stackoverflow.com/questions/66185686/firestore-delete-vs-update-time-and-performance