在20c / 40t 256gb服务器上的~500m窄行的分布式表上创建索引需要花费很多时间，而在我的生活中，我无法理解为什么。
alter table users_userlocation add index date3 (date, user_id);
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height: 200px;
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content: ' ';
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width: 100%;
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transition: all 0s ease;
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bottom: 0;
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.cover a {
color: #fff;
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left: 20px;
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right: 20px;
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position: absolute;
top: 50%;
right: 20px;
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z-index: 10;
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<div class="item">
<div class="item-wrap">
<p>Main content blah blah</p>
<div class="cover">
<a href="#" class="link1" data-toggle="modal" data-target="#myModal">Link1</a>
<a href="#" class="link2" data-toggle="modal" data-target="#myModal">Link2</a>
</div><!-- /.cover -->
</div><!-- /.item-wrap -->
</div><!-- /.item -->
<!-- Modal -->
<div class="modal fade" id="myModal" tabindex="-1" role="dialog" aria-labelledby="myModalLabel">
<div class="modal-dialog" role="document">
<div class="modal-content">
<div class="modal-header">
<button type="button" class="close" data-dismiss="modal" aria-label="Close"><span aria-hidden="true">×</span></button>
<h4 class="modal-title" id="myModalLabel">Modal title</h4>
</div>
<div class="modal-body">
...
</div>
<div class="modal-footer">
<button type="button" class="btn btn-default" data-dismiss="modal">Close</button>
<button type="button" class="btn btn-primary">Save changes</button>
</div>
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</div>
</div>
截至本文，上述情况已经持续了6.5个小时。
答案 0 :(得分：2)
在MemSQL中，索引构建是一个相当慢的操作。通常每个核心每秒转换大约10到2万行。它取决于您添加的表或索引的特征（具有较少索引的表上的瘦行将更快）。索引构建应该对运行的工作负载（一些CPU使用）产生最小的影响。如果您可以共享SHOW CREATE TABLE和CREATE INDEX语句，我可以检查您是否看到异常。