我有大约100,000张借记卡的列表，我想在更新与该卡相关的交易列表时找到相关的卡。我想知道首先加载整个卡片列表并从已加载的列表中查找卡片还是每次使用Entity Framework进行数据库查询是否更为有效？

//Scenario 1:
var cards = db.Cards.ToList();
foreach (var transaction in newTransactions)
{
   var card = cards.FirstOrDefault(x => x.CardNumber == 
   transaction.Transactionmean);
}

//Scenario 2:
foreach (var transaction in newTransactions)
{
   var card = db.Cards.FirstOrDefault(x => x.CardNumber == 
   transaction.Transactionmean);
}