假设我有下表
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css">
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.1.1/jquery.min.js"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.min.js"></script>
<div class="container-fluid">
<div class="row">
<div id="content" class="col-xs-12 col-md-6 col-md-push-6">
content
</div>
<div id="sidebar" class="col-xs-12 col-md-6 col-md-pull-6">
sidebar
</div>
</div>
</div>我的目标是找到一个人的最后一笔交易。我对此的疑问是
+------------+--------+--------+
| date | Seller | Amount |
+------------+--------+--------+
| 2017-03-01 | Anne | 10.00 |
| 2017-03-01 | Pete | 18.00 |
| 2017-03-03 | Dan | 20.00 |
| 2017-03-03 | Dex | 3.00 |
| 2017-03-07 | Pete | 11 |
| 2017-03-07 | Anne | 3.00 |
| 2017-03-08 | Pete | 12.00 |
| 2017-03-08 | Dex | 1.00 |
| 2017-03-09 | Dan | 21.00 |
+------------+--------+--------+
不幸的是，有500万行需要至少9分钟才能完成。有什么方法可以加快速度吗？